If you haven't purchased yet, I found a
different model of power hatch that connects into the car's wiring from the connector behind the HVAC panel. (Note that one is for the Variant - I'm sure they sell one for the normal Golf as well).
Alibaba seller (NOT Aliexpress). But process was much the same, just took a little longer until it shipped, but still arrived within a couple weeks this past summer.
With all of these, don't think you're going to get clear and detailed instructions....you gotta do a lot of figuring on your own (how to run wires, which wires go where). I planned to do a how-to write-up, but it's fallen down the to-do list, unfortunately. 🫤