SSO between 2 wp sites

Hi,
I want to use single sign on with two wordpress sites.
But I′m having trouble getting the client to work.
I found this topic https://www.ads-software.com/support/topic/use-wp-oauth-on-one-wordpress-site-to-login-to-another-wp-site/ and followed the instructions.
I installed https://github.com/perrybutler/WP-OAuth

But it′s still not clear for me what to enter in OAuth Server Endpoint field.
I tried something like this:
https://myserversite.com/oauth/authorize
But it did not work and I didn′t receive any error messages.

Can you give me a hint.
Thank you!