If you are looking to unlock a newer Vivo device or a 2021 device that didn't respond to old tools, you should look into: For MTK-based Vivo phones.
Method 1: Using "Vivo Unlock Tool" / Fastboot Methods (2021 Era)
Professional-level tools often used in 2021 by technicians that offer better compatibility with Vivo MTK/Qualcomm chipsets. These required the hardware dongle.