Man you are fast ! thank you for being this active !
In the description I can read
Send the user you want to authenticate to your registered redirect URI. Then, an authorization page will ask the user to sign up or log into Twitch and allow the user to choose whether to authorize your application/identity system.
I thought Twitch would handle this and send me an iframe to Accept or Decline the authorization and then redirect to the redirect_uri to my dashboard.
I think I’m missing something but I don’t understand : Is the user redirected to Twitch at a specific uri to accept/decline and the redirected to my dashboard ? how is this related to my CORS issue ?