How do I change this event to another? (Data Persistence)

Make the script that you put this into a localscript (And put the localscript into the TextButton). Insert this into the script:

scoreKey = "PlayerScore"

game.Players.PlayerAdded:connect(function(player)
    if player:WaitForDataReady() then
        local leaderstats = Instance.new("IntValue", player)
        leaderstats.Name = "leaderstats"

        local cash = Instance.new("IntValue", leaderstats)
        cash.Name = "Cash"
        cash.Value = player:LoadNumber(scoreKey)

        local xp = Instance.new("IntValue", leaderstats)
        xp.Name = "XP"
        xp.Value = player:LoadNumber(scoreKey)
    end
end)

function Clicked()
local player=game.Player.LocalPlayer
    if player:findFirstChild("leaderstats") then
        player:SaveNumber(scoreKey, player.leaderstats.Score.Value)
    end
end)

script.Parent.MouseButton1Click:connect(Clicked)

It's the same thing, I just added a clicked event for the textbutton to save.