If memory serves they added some Dragonflight API into the Wrath mix. But I could be wrong.
Anyway, this is a 4 month old link to the tradeskill blizzard file from Classic Wrath so hopefully it will provide you with some clues on what you need to change. I've not played with TradeSkill stuff enough, and definitely not recently to offer any suggestions outside of what you already know from earlier incarnations of your addon.
https://github.com/Gethe/wow-ui-sour...adeSkillUI.lua