How would I only give 50 points once?

local GamePassService = Game:GetService('GamePassService')
local GamePassId = 456456

game.Players.PlayerAdded:connect(function(player)
	local stats = Instance.new("IntValue", player)
	stats.Name = "leaderstats"
	
	local points = Instance.new("IntValue", stats)
	points.Name = "Points"
	
	if GamePassService:PlayerHasPass(player, GamePassId) then
		points.Value = points.Value + 50
	end
end)

I want this game to only award points ONCE, which is when they buy it. I don't want it to keep giving 50 points every time they join a server. I'm not sure if I should be using Dev Products or gamepasses.