Can't sign in to iMessage on iOS 15
I installed iOS 15 this morning and now I'm having problem logging into iMessage. I'm being asked to sign in with my Apple ID, but when I do, it takes a long time, then a message says Verification Failed.
I've tried numerous times and the same message comes up.
[Re-Titled by Moderator]
iPad Pro 12.9-inch, 2nd Gen, Wi-Fi