How do I fire server from a script?

Not sure how to explain this, but here it goes.

I have a remote event in replicated storage that, when fired, it gets the player, amount of money to handle, whether to add or subtract said amount, and a code. so when fired from a local script it looks like this (I changed the password):

game.ReplicatedStorage.RemoteEvents.ManageMoney:FireServer(cost,"add","password123")

then, on a script inside ServerScriptService, it handles it like this:

function manage_money(player,amount,operation,pass)
    local name = player.Name
    local plr = game.Players:FindFirstChild(name)
    if pass == "password123" then
        if operation == "add" then
            for i = 1,amount/5 do 
            wait(0.01)
            plr.Settings.Money.Value = plr.Settings.Money.Value+5
            game.SoundService.coins_pay:Play()
        end
        elseif operation == "remove" then
            for i = 1,amount/5 do
                wait(0.01)
                plr.Settings.Money.Value = plr.Settings.Money.Value-5
            end
        end
        elseif pass ~= "password123" then
            if plr:IsA("Player") then
                plr.Settings.HasExploited.Value = plr.Settings.HasExploited.Value+1
                    plr:Kick("You have been kicked for exploiting.")
            end
    end

            end

it all works well for me however confusing it is to any other people looking at my code, but then I encountered a problem: I wanted to give players money for touching a pad at the end of a practice obby, but I cannot do this without a localscript!

please help me with this and tell me if I need to clarify anything :)