I just looked at the code in the xml and copied some stuff.
Viewing post in FS22 PK Bar Liquid Fert/Concord pack edit comments
How I did it was look at the PTO name - so in the instance of the Concord that was "airHose" - to make the hoses hookup they needed to match names between the cart and the toolbar in the xml. At least, that's how I understood it. Tbh I still don't know the specifics of how it all works lol as I got away with it in 22 but not 25