Big surprise: Using Twitter #2FA effectively breaks 2FA because you can take over the account with the (required) phone number:
https://twitter.com/dnlongen/status/1078134961356587017 #twitter #birdsite
Why is this step necessary? mstdn.io might not be the server where you are registered, so we need to redirect you to your home server first.
Don't have an account? You can sign up here