How would I change this to a on click instead of touch?

local MarketplaceService = game:GetService("MarketplaceService")
local TeleportService = game:GetService("TeleportService")
local Players = game:GetService("Players")
 
local teleporter = script.Parent
local showPrompt = true
 
local placeID_Premium = 012345678
 
local function onTeleporterTouch(otherPart)
 
	local player = Players:GetPlayerFromCharacter(otherPart.Parent)
	if not player then return end
 
	-- If the user already has Premium, teleport them to the Premium-only place
	if player.MembershipType == Enum.MembershipType.Premium then
		TeleportService:Teleport(placeID_Premium, player)
	-- Else, prompt Premium upgrade (use debounce to show it only once every few seconds)
	else
		if showPrompt == false then return end
		showPrompt = false
		delay(5, function()
			showPrompt = true
		end)
		MarketplaceService:PromptPremiumPurchase(player)
		warn("Prompted Premium purchase")
	end
end
teleporter.Touched:Connect(onTeleporterTouch)
 
-- If needed, use this event to know when the Premium modal is closed
MarketplaceService.PromptPremiumPurchaseFinished:Connect(function(player)
	warn("Premium modal closed")
end)
 
-- Handle potential Premium purchase from outside the game while user is playing
Players.PlayerMembershipChanged:Connect(function(player)
	warn("Player membership changed; new membership is " .. tostring(player.MembershipType))
	if player.MembershipType == Enum.MembershipType.Premium then
		-- Teleport player to the Premium-only place
		TeleportService:Teleport(placeID_Premium, player)
	end
end)

Change teleporter variable to refer to a ClickDetector.

change teleporter.Touched:connect... to teleporter.MouseClick:connect...

etc.

Its actually pretty simple.

1. Put in a ClickDetector.

teleporter.ClickDetector.MouseClick:Connect(onTeleporterTouch)

assuming this is the line that you wanted converted to click, this should help you out.