Why isn't my DataStore script getting player's data?

The GetSave variable on line 10 is returning a nil value even tho a player has played before on the actual roblox game, not on roblox studio. This is basically causing my script to reset the player's data. Can someone help and explain why?

DataStore = game:GetService("DataStoreService")
Players = game:GetService("Players")
ServerStorage = game:GetService("ServerStorage")
SaveFolder = ServerStorage:WaitForChild('SaveFolder')
DataStorage = DataStore:GetDataStore('test1')

Players.PlayerAdded:connect(function(player)
	local key = player.UserId
	local GetSave = DataStorage:GetAsync(key)
	print(GetSave)
	local PlayerFolder = Instance.new("Folder", player)
	PlayerFolder.Name = 'PlayerStats'
	
	for i, stats in pairs(SaveFolder:GetChildren()) do 
		local NewStats = Instance.new(stats.ClassName, PlayerFolder)
		NewStats.Name = stats.Name
		NewStats.Value = stats.Value
	end
	
	if GetSave then -- if player has data saved
		print(player .. ' has available data') 
		
		for i, stats in pairs(PlayerFolder:GetChildren()) do
			local StatsKey
			
			local success, failure = pcall(function()
				StatsKey = key .. '-' .. stats.Name
				DataStorage:GetAsync(StatsKey)
			end)
			
			if success then
				stats.Value = StatsKey
				print('Loaded ' .. stats.Value .. ' to ' .. stats.Name)
			else
				print('Error when getting data')
				warn(failure)
			end
		end
	else -- Setting default data to player
		print('Setting default data to player')
		
		for i, stats in pairs(SaveFolder:GetChildren()) do
			PlayerFolder:FindFirstChild(stats.Name).Value = stats.Value
		end
	end
end)

Players.PlayerRemoving:Connect(function(player)
	local key = player.UserId
	local PlayerFolder = player:WaitForChild('PlayerStats')
	
	for i, stats in pairs(PlayerFolder:GetChildren()) do
		local StatsKey
		
		local success, failure = pcall(function()
			StatsKey = key .. '-' .. stats.Name
			DataStorage:SetAsync(StatsKey, stats.Value)
		end)
		
		if success then
			stats.Value = StatsKey
			print(StatsKey .. ' was saved')
		else
			print('Error when saving data')
			warn(failure)
		end
	end
end)