Game pass in-game purchase prompt is failing to come up?

I have a script that gives a player a tool immediately after buying a game pass in-game.

Here is what I have

local Id = 793933317
local Gamepass = game:GetService("GamePassService")

script.Parent.ClickDetector.MouseClick:connect(function(plr)
    game:GetService("MarketplaceService"):PromptPurchase(plr, Id)
    if Gamepass:PlayerHasPass(plr, Id) then
        game.Lighting.Sabre:clone().Parent = plr.Backpack
        game.Lighting.Sabre:clone().Parent = plr.StarterGear
end
end)

It should work, however, I'm getting the error

"game passes can only be queried by a script running on a roblox game server"

Also, is this script looped? I.e will it give the player the tool again after dying?

Help would be much appreciated