How to send idToken to firebase backend for validation?

Question

JavaScript

When authorizing a user for a chat, I get an idToken from firebase, but when rendering a new page, I need to check the token I have on the back end. How to implement a request from the client to the firebase backend to get a response about the validity of the token?
The documentation describes the firebase admin library, but it is for the backend.

Answer 1

There is also a Firebase library for the client (it also includes firebase / auth) - doc
Accordingly, you can get the current idToken from it

firebaseApp.auth().currentUser.getIdToken(/* forceRefresh */ true)

where forceRefresh - forced reset of the token to a fresh one. Methods and properties of the library - doc
As far as I understand, the library itself monitors the tokens, if necessary, turned to it.