I have a bot account which I can login in the twitch.tv site but if I try to login in dev.twitch.tv I am always redirected to the login again after enter the 2FA (by app or by SMS).
I tried deactivating the 2FA on that account but then it needs to enter the SMS and again redirected to login form. I also changed my password and reset my 2FA app. With my main account I can login in the dev.twitch.tv but not with my bot account that I use for my application.