How to test PayPal subscriptions in a sandbox?

Question

PHP

I'm trying to set up Paypal subscriptions using a button from the site according to these articles https://habr.com/post/266091/ and https://www.evoluted.net/thinktank/web-development...
But during the test, when the user tries to log in in PP he gets the inscription:
Some of your information isn't correct. Please try again.
The second point to which I did not find an answer: how to get subscriber status from PP? Well, that is, I will need to know if the subscription has ended or extended. I can't find it in the REST API