OAuth2 - authorization server response on re-authorization?

Question

OAuth

Hello!
When authorizing through social networks using OAuth, at the first login, the user enters his login and password on the social network login page (where he was sent by the client) and, if successful, receives a GRANT.
But what happens if the client already has an access_token, but the user logs in from another device, or the cookies are deleted.
Thanks in advance!