Firebase Secret Authentication Returning Null Payload

I used ref.authWithCustomToken(), but the payload that is returned has null properties: auth, expires, token, uid. Except for the 'provider' property which is set to 'custom'. The

Solution 1:

The authData refers to the auth. credential payload (usually a JSON Web Token), which would normally show up in your security rules under the auth variable, for use in restricting read / write access to your Firebase.

When authenticating with a secret, there is no payload and thus the null-value authData, despite being authenticated.