Auth0 & Drupal 7

Good morning to all,
My name is Aris and I am trying to evaluate whether I can use Auth0 with a mix of Drupal 7 and Drupal 8 websites at my charity. Anyone out there that has managed to get it to work (for SSO) on D7?
It works, out of the box, for D8 (auth0 -> applications -> regular web app), but comes up with error 401 not authorised on D7 (same settings).

Thank you in advance