Manual tailgate release D3
And a further tip (at least for D3) is holding the interior lock and unlock buttons together for two seconds forces the tailgate to release.
You’ll need an assistant on hand to open it or it will catch half way.
Important because sometimes it’s the external switch in upper tailgate that fails and not the actuator in lower part. This will confirm what’s not working and keep you going for a while if it’s the switch.
Credit BradC you can also program key fob to pop the tailgate if switch is broken and open single handed but you can’t do this with a broken switch as it needs to ‘see’ the switch. Program fob now before it breaks just in case.