No way to have items with NBT data in villager trades (Enchanting book, Potion)

As far as I am aware there is no way to add custom enchantment books or potions into a villager trade, the item selector only allows choosing a blank enchantment book or potion and the code regenerates because all modded villager trades are handled in [Namespace]ModTrades.Java. So if I can't modify the code or select my enchantment via the item selection menu, how do I implement custom enchantments and potions? Seems like a very important feature in villager trades. I am working in 2023.4