Messy process!
adb reboot edl
/ Vol+ + Power (plug power)MiflashIf possible, avoid- QFIL
VIBEUI_V3.1_1621_5.273.1_ST_Z90_7
Do not use theprerooted
version as this one suffers from a lock screen issue
Note: Do not update this image with the suggested System Update; the patch will fail and the full package will 'remove' the Google Apps.
adb reboot bootloader
fastboot oem unlock-go
fastboot flash recovery twrp.img
fastboot oem reboot-recovery
https://forum.xda-developers.com/lenovo-vibe-shot/development/lenovo-z90-7-vibe-shot-international-t3148018/page236