[Android Central Question]

Hi
I'm forgot my back up pin number.
So pls any help how to unlock my phone with out data lose

[B. Diddy]

Welcome to Android Central! Unfortunately, you really need to remember your backup PIN. When you set up your fingerprint sensor, it asks you to create this backup PIN, and it should also tell you that this PIN is important, because you'll be asked for it periodically, even if the fingerprint sensor is working normally (most notably when doing a cold boot).

If you really forgot your backup PIN and can't get in with the fingerprint sensor, then you probably have to do a hardware key factory reset: https://support.t-mobile.com/docs/DOC-31106. Then hopefully you remember your Google username and password, because the phone will consider this an unauthorized factory reset and ask for that information upon restarting.