im trying to make a like lose ingredients and make cake but it doenst seem to work please help me?

You have everything you need, but you have placed it in the wrong order. If this is a server script, the local player cannot be accessed. So you must use :GetPlayerFromCharacter, like you did later in the script.

script.Parent.Activated:Connect(function()

    local plr = game.Players:GetPlayerFromCharacter(script.Parent.Parent)

    if plr.leaderstats.Ingredients.Value >1 then
        plr.leaderstats.Ingredients.Value = plr.leaderstats.Ingredients.Value -1
        plr.leaderstats.Cake.Value = plr.leaderstats.Cake.Value +1
    else

    end
end)

Is this in a regular script or local script? If it is server script , LocalPlayer cannot be used.