title: Firebase auth set custom expiration time for custom token
body: <p>I am using the firebase custom auth to generate a <strong>custom token</strong> and I was wondering if there was <strong>a way to manually update the token by shortening it based on a specific time a session has finished</strong>. e.g. if a session finishes for like 20 seconds or maybe 5 mins, I could manually update the expiry time of the token</p>
  
  <p>If that is not possible, is there also a way to set a custom constant expiration time for the token e.g. 1 min rather than the 1 hour expiration time</p>