If you are looking to install a custom ROM, I can provide steps to (like TWRP) next. Just

Never, ever use "one-click unlock tools" from unknown sources. They are low quality and often malicious. This guide is your gold standard.

This is the most straightforward, low-risk method, intended for developers.

If you want custom ROMs, sell the Y71 and buy a Redmi or Poco. If you simply need root, use an exploit-based temporary root like mtk-su (works on locked bootloader).

Unlocking the bootloader of your Vivo Y71 can provide you with a range of benefits, including customization, rooting, and development. However, it also carries some risks and precautions. Make sure you follow the instructions provided in this guide carefully and take necessary precautions to avoid any potential risks.

Save it offline – Vivo actively patches EDL access in newer security updates.

Check the toggle; it should show "Bootloader is unlocked." Troubleshooting

fastboot flashing unlock

To successfully unlock the bootloader on your Vivo Y71 with a process, gather these:

Connect the phone to the PC and open a Command Prompt window in your ADB folder.