Only kombis get an internal button PVs don’t get them from the factory as standard
It’s easy anough to add one though, if you have a search of the forum there are a few threads detailing it, you have the choice of buying an aftermarket momentary switch for a few quid or buying a VW one for a lot more if that’s your preference
Either way the wires for the switch just splice into the wires for the external handle so it’s not too bad but if you go down the route of a factory switch then there is no button illumination feed in the tailgate so although it’s easy to get the switch to work it will not illuminate unless you run a wire back into the van and forward to the dash