Adding shop/trade prompts to NPC?

[Tetraspore]

So I've located the scripts that determine which portrait to use, the name of the NPC, and where they are located in game/which building they reside in, and I've also located in the DB where the items for each shop are determined, when they appear, etcetc. What I CAN'T find, is what to edit to add the button to open a shop for any given NPC. Does anyone have experience adding a new NPC shop?

[MentaL]

[Delteros]

You will need to write a new XML, see the zh-tw-x-gm/Data/XML/Default folder

[Tetraspore]

You will need to write a new XML, see the zh-tw-x-gm/Data/XML/Default folder

Ahh, I see. Thank you! Makes sense.