im trying to like if you have 1 cash you can buy 1 ingridients please help me?

For one, you would need a RemoteEvent because if you just do it from that LocalScript it won't replicate to the server, which you want to happen.

Inside of ReplicatedStorage insert a RemoteEvent and name it whatever you want. You'll just have to put the name inside of the script below.

Inside of the LocalScript put this:

local player = game.Players.LocalPlayer -- Instead of doing script.Parent.Parent, you can do this.
local RemoteName = "hi" -- Replace this with the name of your remote.

local RS = game:GetService("ReplicatedStorage") 

local ScreenGui = script.Parent -- Change this to the path of your ScreenGui
local TextButton = script.Parent.TextButton -- Change this to the path of your TextButton

TextButton.MouseButton1Click:Connect(function()
    RS:WaitForChild(RemoteName):FireServer()
end)

Once you've done that we need to make a Script inside of ServerScriptService. Once you insert one you can put the following code:

local RS = game:GetService("ReplicatedStorage")
local RemoteName = "hi"

RS:WaitForChild(RemoteName).OnServerEvent:Connect(function(player)
    if player:WaitForChild("leaderstats").Cash.Value >= 1 then
        player:WaitForChild("leaderstats").Cash.Value = player:WaitForChild("leaderstats").Cash.Value - 1
        player:WaitForChild("leaderstats").Ingridients.Value = player:WaitForChild("leaderstats").Ingridients.Value + 1
    end
end)