If your phone is connected to the internet and logged into a Google Account, you can use the official Google Find My Device platform to remotely erase and reset the lock screen. 2. If you need to flash the firmware (Flashing/Unbricking) Local Upgrade:

If a user tried to root their Vivo V9 Pro and accidentally corrupted the boot.img or userdata partition, the phone would be "hard bricked"—it would not turn on, only recognized by a computer as Qualcomm HS-USB QDLoader 9008 . vivo v9 pro progemmcfirehose 2021

The specific Vivo V9 Pro Prog_EMMC_Firehose file or instructions cannot be provided here as downloading or executing raw firehose binary files can permanently damage (hard-brick) your device if they do not match your exact chipset and firmware version. If your phone is connected to the internet