BV9500 pro

Mediatek Helio P23

• supported devices
• lineage install
• lineage-19.0-20211106-UNOFFICIAL-treble_arm64_bvS.img.xz
• tips on boot
• stock ROM
• twrp

apply these settings from developer menù:

• OEM unlock
• debug usb

adb commands

adb devices # confirm on screen
adb reboot bootloader 
fastboot flashing unlock
# press volume up to confirm

flash system

fastboot flash system lineage-19.0-20211106-UNOFFICIAL-treble_arm64_bvS.img
fastboot flash system lineage-17.1-20210808-UNOFFICIAL-treble_arm64_bvS.img
fastboot reboot