FireClient doesnt works / Argument 1 missing or nil

Good afternoon everyone.
I’ve been trying to make a serverscript fire an event but something doesnt lets it.
It gives error “Argument 1 missing or nil”
I did everything right yet it still gives same error.

This is the script, if you can help me please answer.
local ReplicatedStorage = game:GetService("ReplicatedStorage")
local Players = game:GetService("Players")

local enterEvent = ReplicatedStorage:WaitForChild("enter")

local playersInList = {} -- Keep track of players who triggered the event

enterEvent.OnServerEvent:Connect(function(player, playerName)
	table.insert(playersInList, playerName)
	print(playerName .. " has entered the event.")

	-- Check if all players are in the list
	local allPlayersInList = true
	for _, player in ipairs(Players:GetPlayers()) do
		if not table.find(playersInList, player.Name) then
			allPlayersInList = false
			break
		end
	end

	if allPlayersInList then
		print("waiting 4 seconds and then crashing the lift with camera shake")
		wait(4)
		game.ReplicatedStorage.shake:FireClient()
	end
end)

:FireClient() takes the player as the first argument…

You need to include the player to fire the event to. If you want to do this for all players, use FireAllClients()