How can I confirm values passed through remote event ?

I would like to confirm values passed through a remote event for a anti-exploit system:

Local Script:

local char = script.Parent
local RemoteEvent = game.ReplicatedStorage.Events.RemoteEvent
local uis = game:GetService('UserInputService')
local combinded = {} -- to pass more value through if necessary

uis.InputBegan:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.B then
		BindableFunc:FireServer(combinded)
	end
end)

Server Script:

local RemoteEvent = game.ReplicatedStorage.Events.RemoteEvent

function Key(combinded)
	local RandNumber = math.random(1, 1000000)
	local Letters = {'a', 'b', 'c'}
	combinded = RandNumber
end

RemoteEvent.OnServerEvent:Connect(Key)

I have got this far but don't understand how I could possibly check the values being passed through, I thought about using a if statement, but don't understand how that would work either.

type

print(combinded) at the top of the key function