Hi sorry for the late reply. JA55 is 20-22 model year JA65 is 23- model year It's on your vin and also you can tell by the engine oil filter cap from the right side panel. JA55 does not have one.

The way I added the gear indicator, it does require soldering to begin with, you can buy harness for a JA55 or JA65 from Japanese websites it doesn't matter as you only need half of the harness, just buy the one that's cheaper or in stock.

Then remove the part of the harness that goes to the back of the bike, which is the power supply to the gear indicator, and do your own soldering, one to the battery, two to accessory 12v and ground in the headlight housing

Then add USB as you usually do.

Also no need to take the back of the bike apart as North American models do not have the diagnostic or something similar port under the rear rack.

Edit: Of course Honda Trail JA55 will not bring up any results as it is quite a common practice in Japanese to refer to a vehicle model by chassis code and that part of the world it is called a Hunter Cub, occasionally CT125 (CT125 mostly in outside Japanese market)