Here is a blank aia with a refresh button, so that the user can keep the session alive, as long as their existing session has not passed the hour.
You could add a clock to monitor the signin time and either automatically refresh, or alert the user that they need to do so to remain signed in, and to prevent them from signing in on another device 
fbSingleSignIn_Timestamp_Refresh_blank.aia (6.9 KB)
Be aware that the keys for the idToken and refreshToken are different in the Signin json and in the Refresh json.
SignIn keys returned are: idToken & refreshToken
Refresh keys returned are: id_token & refresh_token
This is reflected in the blocks...