The audience for which this token is intended.
This value is a string equal to your Firebase project ID, the unique identifier for your Firebase project, which can be found in your project's settings.
Time, in seconds since the Unix epoch, when the end-user authentication occurred.
This value is not set when this particular ID token was created, but when the
user initially logged in to this session. In a single session, the Firebase
SDKs will refresh a user's ID tokens every hour. Each ID token will have a
iat value, but the same
The ID token's expiration time, in seconds since the Unix epoch. That is, the time at which this ID token expires and should no longer be considered valid.
The Firebase SDKs transparently refresh ID tokens every hour, issuing a new ID token with up to a one hour expiration.