How can I limit the number of tools in the hotbar or backpack?

Hey guys, I'm currently trying to create a handball game, I turned off the hotbar, the backback and so on with a localscript:

local StarterGui = game: GetService ("StarterGui") StarterGui: SetCoreGuiEnabled (Enum.CoreGuiType.All, false) StarterGui: SetCoreGuiEnabled (Enum.CoreGuiType.Chat, true)

In a handball game you need a ball, of course, which you can hold in your inventory with a click detector in a part. Now everything worked out, the players can now get handballs and since I have issued the backpack you can not see this handball / tool in the bottom of the Hotbar which I think looks much better. Unfortunately there is a small problem if the players now have more than one ball in their inventory, they cannot throw it because there is no backpack to stun these balls, so the balls are picked up at the same time and you cannot throw them because they glitch into each other. Therefore I wanted to ask for a method with which you can ONLY have 1 slot / inventory space. So that only one ball can be picked up and they don't glitch into each other. Now my question to you would be how do I get that everyone has only one inventory place. Or whether I have to do that you can only have the tool once (unfortunately I don't know how that works).

I thank you in advance for the help!

PS Kidaiichi