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)