Unlock and format vivo y81 with mrt and fix google frp with miracle.
This way is working if with y83 boot option failed. With boot y83 the result in mrt interface is succes,but the phonecode is still there and not wiping. With boot x21i from adb ( boot with adb in advance recovery mode ) or meta mode only succeed for formating user data,but not work for reset google frp. So use miracle in android extra tab with oppo fix frp tab ( boot with adb in advance recovery mode).