Category key for Animation asset type?

I am trying to add categories with factories for custom asset type ( the groups you see when you click new asset in content browser) I want to add my asset to Animation submenu.

I am doing this using “AssetTools::RegisterAdvancedAssetCategory”

however it needs the category key in addition to category name to have it in the same category otherwise it just makes another entry with the name animation.

Does anyone here know what category key the engine uses for its animation category?

If I remember right that’s just an enum index;
I’m away from Pc now I can’t really check it.