Error code: 80019 - Auth Server Rejecting Request

This error is raised by the client libraries in https://ably.com/docs/auth#token-process.  This error means that the library attempted to obtain a token using the client-supplied authCallback or authURL, and the attempt failed. For example, this could be because there was an error or exception invoking the callback. If the request to the auth server fails then an 80019 error is raised.

The error returned by the library (ie the error with the 80019 code) will have a cause field which will contain the underlying error from the authCallback or authURL.