Please help. ipad air 2 can't get past the passcode page, its frozen

We recently enabled the thumb print as the login for our iPad air2.

2 weeks later the login page started to freeze and we are unable to use the passcode touch screen page (its frozen and doesn't let you enter the passcode).

Whilst we had access to the device we went into settings but were locked out from the passcode section. It was ghosted.

As it has been more than 48hrs since logging in we are unable to access the device at all (passcode screen frozen).

We have an iCloud account and a recent backup. Im assuming we need to restore factory settings and the restore from backup. I can't work out how to do this.

Do I need to remove the device from the icloud account?

TIA