you can use itAffiliateWP Plugin to set up an affiliate marketing program on your website.

For what purpose? Users will promote your stuff online, which is good for SEO.

Demo:https://affiliate-WP.com/

Features of AffiliateWP - Affiliate Plugin for WordPress

• For every new sale you refer, you will earn a 20% commission.
• To use on your website, you can access a set of banners and logos.
• In your membership section, you may see access data, referrals, and payment updates.
• To optimize revenue potential, please track cookies within 30 days of your initial visit.
• With the help of our professional affiliate managers, you can get help with affiliate marketing.
• Unlimited commission bonus
• Pay monthly via PayPal (minimum $50.00).

Changelog AffiliateWP WordPress plugin cancelled for free

v2.8.3, January 6, 2022
Fixed: Some user metadata is not correctly migrated when upgrading to 2.8

v2.8.2, December 23, 2021
Fixed: WooCommerce: Failed referrals are unexpectedly displayed in order views
Fixed: Restrict Content Pro: Referrals not created with an affiliate link if payment contains a discount code
Dev: Make it possible to enable or disable debug mode from the command line

v2.8.1, November 30, 2021
Improved: Introduce a 'failed' referral status for draft referrals that failed to become pending
Improved: Add Payouts Service support for six additional countries: Egypt, Israel, Croatia, Iceland, Uruguay, and Peru
Fixed: Block registration Confirm Password label not working
Fixed: Passwords entered on block-based registration forms don't get saved
Fixed: Undefined index for checkbox fields in block-based forms
Fixed: Affiliate registration not always working for existing users
Fixed: Add referral screen allows negative amounts to be entered

v2.8, November 11, 2021
New: Build custom affiliate registration and login forms using the block editor
New: Add controls for formatting dynamic coupons based on affiliate info
New: Merge Blocks add-on into core
New: Introduce a draft referral status to improve logging of referral history
Improved: Requires WordPress 5.2 or newer
Improved: Introduce a filter in the Affiliate Area > Coupons template
Improved: Introduce a new 'type' column in the Coupons database table
Improved: Introduce a filter in the list table class for more easily customizing filtered views
Improved: Migrate legacy affiliate information from user meta to affiliate meta
Improved: Display context in integration logs
Improved: Increase coupon code length to 191 characters
Fixed: Fix strings with malformed placeholders causing errors in the Danish translation
Fixed: Improve error handling in the licensing API
Fixed: Prevent changes to the conversion rate when updating a campaign

v2.7.8, November 3, 2021
Improved: Introduce a Cookie Compat Mode for use with specialized caching setups
Fixed: Avoid a fatal error when viewing Settings with the Danish translation

v2.7.7, October 26, 2021
Fixed: Check for core and add-on updates no more than once per hour

Version 2.7.6, October 8, 2021
Improved: Update the Payouts Service URL everywhere for consistency
Fixed: Fix a typo in the {amount} merge tag in the nl_NL translation

v2.7.5, September 21, 2021
Fixed: Mitigate potential SQL injection in two internal database APIs

v2.7.4, July 28, 2021
Fixed: Campaign conversions are not being properly recalculated in some circumstances

v2.7.3, July 19, 2021
Improved: Improve styling and integration with the WooCommerce coupon editing interface
Improved: Soft bump the PHP minimum to 7.0
Fixed: Uninstall crashes following changes to the bootstrap introduced in 2.7
Fixed: REST endpoints accepting IDs and arrays of IDs should properly handle for arrays

v2.7.2, July 8, 2021
Fixed: Fix Pantheon-specific cookie prefix delimiter

v2.7.1, July 5, 2021
Improved: Add specialized cookie handling for the Pantheon edge network
Improved: Notate in the System Info log whether the site is running on the Pantheon edge network
Improved: Pass the referral object to the affwp_auto_complete_referral filter
Improved: Add select2 to core for add-ons to use
Fixed: affwp_is_affiliate query variable only works in admin areas

2.7, June 22, 2021
New: Require WordPress 5.0 or newer
New: Require PHP 5.6 or newer
New: Soft-discontinue five integrations (more information):
ExchangeWP (iThemes Exchange)
Jigoshop
MarketPress
Shopp
WP eCommerce
Improved: Implement partial activation for a better activation experience sans minimum requirements
Improved: Add unique id attributes to the output for each registered setting
Fixed: PHP 8 compatibility fixes
Fixed: WooCommerce: Don't override product rate with affiliate rate in certain circumstances
Fixed: Querying with a custom fields param value via REST triggers a fatal in some circumstances
Fixed: Use translatable labels for statuses in the Affiliates list table
Fixed: Add missing translator comments for all localized strings containing placeholders
Fixed: Restore the ability to save affiliate rate and rate type to empty
Fixed: Ensure affiliate ID is cast as an integer when derived from a coupon
Dev: Upgrade the ParseCsv library to v1.3.0
Dev: Audit and overhaul inline documentation throughout the plugin
Dev: Introduce an `affwp_plugins_loaded` hook for add-ons to bootstrap on
Dev: Introduce `affwp_get_{object}_by()` helper functions for most core objects
Dev: Convert Campaigns to use a standard database table instead of a MySQL view
Dev: Improve campaign management with the introduction of a fully-qualified Campaign object

= v2.6.8, May 3, 2021 =
New: Add support for 7 more countries in the Payouts Service:
Argentina
Brazil
Costa Rica
India
Indonesia
Mexico
Thailand
Improved: Ensure all Payouts Service requests are made to official REST endpoints
Improved: Update payout record if a Payouts Service payout method changes
Improved: Standardize headers sent with every Payouts Service request
Fixed: Wrong URL displayed in notice when creating a Payouts Service account with a registered email address

= Version 2.6.7, March 25, 2021 =
Improved: Improve upgrade routine notices by including the AffiliateWP version number
Improved: Add the ability to list affiliates, payouts, referrals, and visits by a date range with wp-cli
Fixed: WooCommerce: Order status of Refunded should always change referral status to Rejected if enabled
Dev: Fix the order of arguments passed to affwp_auth_hash() in Affiliate_WP_REST::get_token()

= v2.6.5, February 19, 2021 =
Fixed: Avoid a fatal error in User Switching compat if the affiliate user no longer exists
Fixed: Contact Form 7: Warning if the CF7 PayPal add-on is not installed
Fixed: Referral batch import not accepting Username as Affiliate ID
Fixed: Payouts Service: Use the correct documentation link

= Version 2.6.4, January 25, 2021 =
New: Add Hungary to the list of countries supported by Payouts Service
Improved: Add support for referral types in referral imports and exports
Improved: Add User Switching 'Switch To' support to the affiliates list table
Improved: Indicate whether dynamic coupons is set up and enabled in the System Info file
Improved: More efficiently check for add-on updates
Fixed: Avoid a fatal when checking self-affiliate REST requests
Fixed: Resolve a conflict with WooCommerce Subscription's "sudo coupons" feature
Fixed: Batch processor does not always visually update when running an importer
Fixed: is_infinite() expects parameter 1 to be float, string given
Fixed: Thai translation not working
Dev: Update core registry to support non-array registrars

= v2.6.3.1, January 5, 2021 =
Fixed: WooCommerce variable product rates can inadvertently get set to 0.00 in some cases

= Version 2.6.3, December 15, 2020 =
Improved: Dynamic coupons should be generated when auto-registering new users as affiliates
Fixed: Recount Stats tool doesn't account for setting zero-based affiliate stats
Fixed: WooCommerce: Prevent non-period decimal separators from getting stripped from product referral rates
Fixed: $category_id is undefined in EDD's get_referral_total() method
Dev: Add compatibility for WP_REST_Request::has_param() pre-WordPress 5.3

= v2.6.2, November 26, 2020 =
- New: Add a REST endpoint for retrieving campaign data
- New: Support MySQL date_format when querying referrals
- New: Introduce affwp_is_affiliate_area() to determine whether you're in the Affiliate Area
- Improved: Make it possible to search for individual visits in the Visits screen
- Improved: Make it possible to use affwp_get_report_dates outside the context of $_GET
- Fixed: Can't delete admin affiliate
- Fixed: Error when an array is passed when registering Payouts Service admin notice
- Fixed: Affiliate Area missing "Your affiliate ID is:" when settings are not yet saved
- Fixed: affiliates/ endpoint cannot be used by non-admin affiliates

= v2.6.1 =
- New: Auto create tracked discounts/coupons for integrations
- New: Introduce functions for emulating REST API calls
- New: Bundle a core requirements check class for future use
- New: Soft bump PHP minimum to 5.6
- Fixed: PHP notice when retrieving instance of an integration class