Hi @Oxyrus
From your /authorize request ,
I can see the client id as : Client ID: GIkKJ0PPJp78oXxS974K6r0ROLPCFGIE
That means in the Application configuration of the API debugger extension you have added this application(with client id : GIkKJ0PPJp78oXxS974K6r0ROLPCFGIE), you can find the application with this client id on your dash board.
You will need to add the call back url : Auth0 - Protocol Debugger in the Allowed Callback URLs of this application with client id : GIkKJ0PPJp78oXxS974K6r0ROLPCFGIE.