Auth0 $attributes not working


I’ve been using Humhub (what is build on top of Yii) for sometime now. Since I’ve been using more webapps I started implanting authentication with Auth0. Unfortently everything I did to make it work didn’t succeed. I have created a authclient and all the requests that are made contain a error: ‘yii\base\ErrorException: Undefined index: user_id’. So I thought that maybe I could make a vardump of the variables that are send from the Auth0 server to check if there is a variable ‘user_id’.
So how do I accomplish this? (And maybe how do I add Auth0 as a authclient :wink: )

Thanks in advance!