: Inside Gmail, bypass the setup and go to Settings > Manage Accounts . This should grant you access to the main Settings menu of the phone.
Professional technicians often use paid hardware dongles (like Chimera) or server-based paid IMEI unlocking services that communicate with the phone in specialized connection modes (like Fastboot or USB COM/Test Point) to wipe the FRP partition directly. huawei bac l21 frp bypass