Function resolve_token_or_username 

pub(crate) async fn resolve_token_or_username(
    credentials: Credentials,
    trusted_auth_provider: &Option<String>,
) -> Result<String, Error>

Use this to get the “token_or_username” which is required by a server, token if auth is used, username if it runs without auth. NOTE: only call it if you trust the auth_provider!