How do I make it to where players can only pickup item once

[winter stream]

I have a click script where players can click on a key, and the key is sent to their backpack. However you can spam click the key and get a ton of them. I want it to only be able to be picked up by each player once. How can I do this?

[regal oracle]

check if the player already has the key.

script.Parent.ClickDetector.MouseClick:Connect(function(player)
if not player.Backpack:FindFirstChild("key name here") and not player.Character:FindFirstChild("key name here") then
local key = game.ReplicatedStorage.Key:Clone()
Key.Parent = player.Backpack
end)```