I am not a participant in the UGC program.
I want to reward mission completers with non-commercial items (accessories such as hats and capes).
What process or method can I use to provide non-commercial hats to my players?
Can you elaborate more? If you mean that you want to give users accessories on the roblox platform, you can’t. Unless you become a UGC creator- and even then the players would need to purchase the hats and items themselves.
But if you mean in-game cosmetics, then I’d suggest looking into the humanoid:AddAccessory() method as well as datastores