Can I have an example implementation of a request (?) WP + WP OAuth Server + SPA?

Question

JavaScript

The internet is full of examples of how to get a post post and stuff with new wp features by adding ?access_token={the_access_token} to the request link. But here the problem is a bit different.
I have a react js application (client side script execution) and they have different databases with wp. How to implement requests to the application only from registered wp users from a special section of the site (./APP/admin/* and ./APP/user/*)? If you can article or lesson tell me.

Answer 1

a small tutorial on how to make authorization for WP via OAuth is here
www.sitepoint.com/wp-api-and-oauth-using-wordpress...
it is a bit outdated, you don't need to install the plugin.
but the general course of action is about the same and remained