I have the problem that I have entered a number on my Twitch account in the Settings → 2FA Authentification, to which I no longer have access… Can the number be changed somehow or the 2FA deactivated?
This could help. 👍
https://support.authy.com/hc/en-us/articles/360034552534-Disable-or-Remove-Authy-2FA-from-Twitch
If that doesn't work, you should contact Twitch Support.