Verification failed

You need another trusted device or telephone number.

See Two-factor authentication for Apple ID - Apple Support:

A trusted device is an iPhone, iPad, or iPod touch with iOS 9 and later, or a Mac with OS X El Capitan and later that you've already signed in to using two-factor authentication.

Get a verification code and sign in with two-factor authentication - Apple Support

Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone, iPad, or iPod touch https://support.apple.com/en-us/HT201559

Try a forced restart.

Reset Device. https://support.apple.com/en-us/HT201412

If necessary

Hard reset. https://www.wikihow.com/Hard-Reset-an-iPhone

Do a backup and try a factory reset. Then restore from your backup.

Restore to Factory setting. https://support.apple.com/en-us/HT201252

Backup - Restore your device from an iCloud or iTunes backup. https://support.apple.com/en-us/HT204184