how to temporarily disable open tailgate alarm

Provided you’re familiar with how stuff works (?) .. You can try manually closing the lift gate ‘latch’ - using a screwdriver, or similar tool, to move latch lever to the *closed position* .. Since the ajar sensor is located within the latch assembly - that ‘may’ silence the gate open alarm. However you MUST manually RE-OPEN the ‘latch’ once again before closing the lift gate!! There is no easy - ‘push a button’ option.