Hi Apotheosis Dev, could you please help me how to use your API in this case ?

I want to spawn a boss by addfreshentity() with your apotheosis effect, the input will be mob id, apotheosis boss grade (ex: rare, legendary, mythic,...)
How can I call your API to spawn a specific boss with mob id, apotheosis boss grade input ?
Or maybe using nbt tag for adding apotheosis boss effect? Because my mod can addfreshentity() with nbt tag

BRs,
pla

You cannot spawn an arbitrary entity as a boss. Bosses must be provided via datapack.

The code you might want to look at is here https://github.com/Shadows-of-Fire/Apotheosis/blob/1.21/src/main/java/dev/shadowsoffire/apotheosis/mobs/types/Invader.java#L146

You can view usages of that symbol to figure out how it works. A simple reference is the BossSummonerItem https://github.com/Shadows-of-Fire/Apotheosis/blob/1.21/src/main/java/dev/shadowsoffire/apotheosis/item/BossSummonerItem.java#L44