Ah I see, I thought you were going for a big chunky 4 channel amp.
I've just remembered the 12v and and earth (pins 22 & 23) need a wider male terminal. I believe it's VW part number 000979226A, which is a TE Connectivity JPT 2.8 gold plated male terminal for wires up to 2.5mm². This is my source for VW terminal info:
http://www.t-g-s.de/epc/index.php5?title=Leitungssätze/pigtails_2,5qmm The part number for your blue amp connector is 1J0962623A, the female end in the connector is 000979225 and the 226 is the male end.
The male terminals won't lock into place so you'll need to wrap electrical tape around the wires and connector to hold them in place. I used these ones for my Bose install, the seller does different sizes for thicker or thinner wires.
https://cyberpunkclothing.net/ I have crimping tools and found that they didn't work, so I used a pair of standard pliers. If they were still a bit loose I stuck a blob of solder on them.
The easiest route for your wires is down the drivers side. The carpet sits on a couple of inches of foam so you can push your wires down the gap between the foam and the sill. Unfortunately due to the way it's designed you'll need to remove/loosen lots of trim just to get the sill trims off - A pillar, B pillar, dash side, slim trim behind the dash side, roof airbags, rear seat base, side of rear seat cushion and the boot trims. It may sound daunting but the Total Technik tutorials on YouTube make it easy. It took 3 days to get my Bose install done but that had a lot more wiring, book a couple of days off work and make sure you have food in the house before you start

Some people say running the wires down the middle is easiest but I've read on several forums that the rear footwell section is so tight that you need to loosen the seats & carpet which means loosening all the trim I mentioned above.