: Ensure you have the X722 (Snapdragon 820 variant) and not the X720/X727 (Snapdragon 821), as flashing the wrong ROM will hard-brick the device.
You cannot use the stock recovery to flash this because LeEco disabled local updates on the X722. You must use : official letv leeco le pro 3 elite x722 stock rom link
Step 5 — Flash with QFIL (example flow) : Ensure you have the X722 (Snapdragon 820
Since official LeEco links are dead, your best bets are community-driven archives and forums that have mirrored the files: official letv leeco le pro 3 elite x722 stock rom link