How would I make a conditional AFK damager?

I have searched for this on YouTube and forums but it’s mostly talking about exploiter scripts. I need to make a script that damages players whilst afk and while another condition is met. I spent about two hours and am unsuccessful. All help is appreciated.

You could try using the Player.Idled event.

Player.Idled:Connect(function(IdleFor)
    print(Player.Name.." has been idle for "..IdleFor.." seconds!")
end)

The above solution will work fine, but why do you want to damage afk players?

To ensure they are moving during a running game