[AC Question]

it keeps asking for my backup pin and i forgot it

[B. Diddy]

Welcome to Android Central! Sorry, but you have to remember your Backup PIN. Your only option at this point is to do a factory reset, and then enter your Google username and password when the phone boots back up (which is due to Factory Reset Protection). The phone's data will be lost, of course, unless you backed it up or synced it somewhere.