(
* [[https://community.e.foundation/t/device-support-project-treble/19645|supported devices]]
* [[https://www.getdroidtips.com/lineage-os-17-1-blackview-bv9500-plus-android-10/|lineage install]]
* [[https://sourceforge.net/projects/andyyan-gsi/files/lineage-19.x/|lineage-19.0-20211106-UNOFFICIAL-treble_arm64_bvS.img.xz]]

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