Enable Developer Options: Settings → About phone → Tap Build number 7 times.

Repacking a TWRP (Team Win Recovery Project) image for the (released in 2018) typically involves modifying an existing recovery image to fix specific bugs, such as touch screen issues or partition mounting errors common on this model. ⚠️ Essential Prerequisites Vivo Y71 Refurbished - Back Market

that has been specifically adjusted—or "repacked"—to work with a particular device’s unique hardware or software constraints. For a device like the

Repacking, in the context of Android device modification, refers to the process of re-packaging a ROM or firmware image to make it compatible with a specific device. This can be necessary when trying to install a custom ROM or firmware on a device that wasn't originally intended to run it. Repacking can be a complex process, but it can also provide users with a wide range of customization options.

After installing the repack, rooting is straightforward:

You generally cannot flash TWRP without an unlocked bootloader.