Display different Website Content based upon Site Referrer / Affiliate Link - for cloaking

Hello, I was wondering if anyone here knows a way to display different website content based upon site referrer / affiliate link.

I want to setup something on my website...

So let's say 1 visitor just goes to a webpage directly and another visits via an affiliate link such as examplesite.com/?rel=1 , I would like to setup something so that the user who visits the webpage via the affiliate link will see different content than someone who visits the webpage from another source.

Does anyone have advice or a solution for this?

2. Would it be possible to setup something so anyone who visits examplesite.com without an affiliate link gets redirected to another url, while anyone who visits via an affiliate link such as examplesite.com/?rel=1 - doesn't get redirected.

Thanks

Will pay if you can help

You can do this in Javascript, I think this is what I did when I finished a similar thing recently;

const isAffLink = window.location.href.includes('?rel=');

isAffLink will be true if '?rel=' is in the url.

That would be one way to do it.