How to accept payments via Paypal through a button on the site?

Question

PayPal

I can't find a proper article. The ones I found are outdated because Paypal's documentation has changed.
So, there is a site, no matter what. You need to add a button with a redirect to Paypal and then process a post request or webhook from Paypal with a transaction number and other details. How to do it, where exactly is it in the documentation?
Do not offer SDK from Paypal.

Answer 1

https://developer.paypal.com/docs/classic/button-m...
in general, with an account in Sanbox Paypal it is much easier to understand their docks