first, create a part, and then insert a script and a ClickDetector inside of it. the hierarchy should look like this:
next, create a ShirtGraphic instance inside of ReplicatedStorage and name it T-Shirt. paste in the id of your t-shirt into the shirt graphic. you can also use decals if you wish!
after youve created your t-shirt, paste in this code to your script.
local ClickDetector = script.Parent.ClickDetector
local Shirt = game.ReplicatedStorage["T-Shirt"]
ClickDetector.MouseClick:Connect(function(Player)
local Character = Player.Character
local NewShirt = Shirt:Clone()
NewShirt.Parent = Character
end)
after that, you’re done!
if you would like me to explain anything in further detail, let me know!