How to make a data persistence leaderboard?

So something is wrong idk what no errors because i cant test in studio.

Saving not working and loading. And the other stats are not showing up.

Does someone know what i did wrong? Thanks

Full script:

levelKey = "PlayerLevel"
exppKey = "PlayerExp"
wiKey = "PlayerWi"
loKey = "PlayerLo"
moKey = "PlayerMo"
coKey = "PlayerCo"
troKey = "PlayerTro"
geKey = "PlayerGe"
local maxlevel = 250

game.Players.PlayerAdded:connect(function(player)
    if player:WaitForDataReady() then
        local stats = Instance.new("IntValue", player) 
        stats.Name = "leaderstats"
        local level = Instance.new("IntValue", stats) 
        level.Name = "Level" 
        level.Value = 1
        level.Value = player:LoadNumber(levelKey)
        local expp = Instance.new("IntValue", stats) 
        expp.Name = "XOP"
        expp.Value = player:LoadNumber(exppKey)
        expp.Value = 0 while wait() 
        do local extralevel = level.Value 
            local expneed = ((extralevel * 2) - 1) * 50 
            if level.Value < maxlevel then 
                if expp.Value >= expneed then level.Value = level.Value + 1 
                    expp.Value = expp.Value - expneed 
                end 
            end 
        end
        local win = Instance.new('IntValue', stats)
        win.Name = "QW" -- Wins (Dd)
        win.Value = 0
        win.Value = player:LoadNumber(wiKey)
        local lose = Instance.new('IntValue', stats)
        lose.Name = "LP" -- Loses (De)
        lose.Value = 0
        lose.Value = player:LoadNumber(loKey)
        local money = Instance.new('IntValue', stats)
        money.Name = "DHJK" -- Money (Df)
        money.Value = 0
        money.Value = player:LoadNumber(moKey)
        local coin = Instance.new('IntValue', stats)
        coin.Name = "IPE" -- Coins (Dg)
        coin.Value = 0
        coin.Value = player:LoadNumber(coKey)
        local trofee = Instance.new('IntValue', stats)
        trofee.Name = "TR" -- Trofee (Dh)
        trofee.Value = 0
        trofee.Value = player:LoadNumber(troKey)
        local ge = Instance.new('IntValue', stats)
        ge.Name = "KLOPT" -- Gems (Di)
        ge.Value = 0
        ge.Value = player:LoadNumber(geKey)
    end
end) 

game.Players.PlayerRemoving:connect(function(player) 
    if player:FindFirstChild("leaderstats") then
        player:SaveNumber(levelKey, player.leaderstats.level.Value)
        player:SaveNumber(exppKey, player.leaderstats.expp.Value)
        player:SaveNumber(wiKey, player.leaderstats.win.Value)
        player:SaveNumber(loKey, player.leaderstats.lose.Value) 
        player:SaveNumber(moKey, player.leaderstats.money.Value) 
        player:SaveNumber(coKey, player.leaderstats.coin.Value) 
        player:SaveNumber(troKey, player.leaderstats.trofee.Value) 
        player:SaveNumber(geKey, player.leaderstats.ge.Value)     
    end
end)

Edit*