How do you make a script that kicks after a humanoid is dead?

Hey! I noticed the last answer was not working for you so I made a revised version. Put this in a normal Script inside of the NPC:

local hum = script.Parent.Humanoid
game.Players.PlayerAdded:Connect(function(Player)
    Player.CharacterAdded:Connect(function(Character)
        hum.Died:Connect(function(Death)
            wait(30)
            Player:Kick("You Died") -- Put your custom message here
        end)
    end)
end)

Use the following:

Players.PlayerAdded - See Docs

Player.CharacterAdded - See Docs

Humanoid.Died - See Docs

Players:GetPlayerFromCharacter() - See Docs

Player:Kick() - See Docs

With these elements in mind, you can create the following example script:

game.Players.PlayerAdded:Connect(function(plr) -- Bind this function to when someone joins the game
    plr.CharacterAdded:Connect(function(char) -- Within that player, when it's character is added, bind this function
        char.Humanoid.Died:Connect(function() -- Then, within that character, search for the humanoid, and bind a function to when it dies
            wait(30) -- Optional, wait before kicking. Mind that the character may respawn during this period.
            plr:Kick("Custom Message") -- Kicks the player
        end)
    end)           
end)