The keyword "verified" is the most critical part of the search query "download unlock bootloader vivo fix tool v20 verified." The internet is rife with fake tools, malware, and clickbait. Downloading an unverified tool from a random forum or file-hosting site can lead to severe consequences:

Before you rush to download, understand the risks. A "verified" tool in the hacking/modding community does not mean it is certified by Google or Vivo. It means that experienced users have scanned the executable and confirmed it contains

In the newly visible Developer Options , toggle on OEM Unlocking and USB Debugging .