I've tried to add potions as bounties but each time i specify a potion it comes up as "uncraftable potion" yet when i submit the right potion it still gives me back my bounty reward? Basically it works except that it says "uncraftable potion" so i don't know which potion I have to make. Even using the wiki's exact code causes this same problem.
"content": "minecraft:potion",
"amount": {
"min": 1,
"max": 3
},
"unitWorth": 300,
"weight": 100,
"stages": ["a", "b"],
"nbt_data": "{Potion: "minecraft:healing"}"

You need to put a \ before every quote inside of your JSON quotation marks, otherwise it's not a valid JSON file.

Without the slash, it thinks that those normal quotations are part of the JSON file, and the NBT is invalid (which means it is not a valid potion)

So replace:

"nbt_data": "{Potion: "minecraft:healing"}"

With:

"nbt_data": "{Potion: \"minecraft:healing\"}"

The wiki does this as well, so you're obviously not using the exact same code as the wiki :^)

I hope that helps!

Closing, never got a response and it's been well over two weeks