How to filter custom chat?

It's supposed to filter chat

local ChatService = game:GetService("Chat")

local chatMessage = game.ReplicatedStorage.ChatMessage


local function onChatReceived(sender, message)

    for _, player in pairs(game.Players:GetPlayers()) do
        if sender ~= player then
            local filteredMessage
            if game:GetService("RunService"):IsStudio() then

                chatMessage:FireClient(player, sender, message)
            else
                local success, filteredMessage = pcall(function() return ChatService:FilterStringForBroadcast(filteredMessage, sender, player) end)
                if not success then
                    filteredMessage = "<Failed to filter message>"
                end
                chatMessage:FireClient(player, sender, filteredMessage)
            end
        end
        end
end


chatMessage.OnServerEvent:connect(onChatReceived)

-- ROBLOX Services
local ContextActionService = game:GetService("ContextActionService")

-- Static variables
local MAX_MESSAGES = 10
local MESSAGE_HEIGHT = 25
 local NUM_MESSAGE = 0

-- Local variables
local player = game.Players.LocalPlayer
local messages = {}
local chatMessageEvent = game.ReplicatedStorage.ChatMessage

-- Variables for GUI elements
local chatScreen = script.Parent
local chatFrame = chatScreen:WaitForChild("ChatFrame")
local chatInput = chatFrame.ChatInput
local messageFrame = chatFrame.MessageFrame
-- Make a copy of the message that will be used later
local messageTemplate = messageFrame.Message:Clone()
messageFrame.Message:Destroy()


local function addMessage(sender, message)
    -- Check if the number of messages has hit the maximum
    --if #messages >= MAX_MESSAGES then
        -- If so remove the oldest message from the table
    --  table.remove(messages, #messages):Destroy()
    --end

    -- Shift all of the messages up one slot

    -- Create new message GUI elements and add to the message table
    if messageFrame:FindFirstChild("LastMessage") then
        messageFrame.LastMessage.Name = "Message"
    end
    local newMessage = messageTemplate:Clone()
    newMessage.NameLabel.Text = sender.Name .. ": "
    newMessage.Content.Text = message
    newMessage.Name = "LastMessage"
    newMessage.Parent = messageFrame
    newMessage.Position = UDim2.new(1, 0, 0, NUM_MESSAGE*MESSAGE_HEIGHT)
    newMessage:TweenPosition(UDim2.new(0, 0, 0, NUM_MESSAGE*MESSAGE_HEIGHT), "Out", "Quad", 0.4,false)
    if newMessage.Position.Y.Offset ==  200 then
    messageFrame.CanvasSize = messageFrame.CanvasSize + UDim2.new(0, 0, 0, 25)
    messageFrame.CanvasPosition = messageFrame.CanvasPosition + Vector2.new(0, 25)
    elseif newMessage.Position.Y.Offset > messageFrame.eh.Position.Y.Offset then
        messageFrame.CanvasSize = messageFrame.CanvasSize + UDim2.new(0, 0, 0, 25) 
        messageFrame.CanvasPosition = messageFrame.CanvasPosition + Vector2.new(0, 25)
    end
    table.insert(messages, 1, newMessage)
    NUM_MESSAGE = NUM_MESSAGE + 1
end

-- Function when the input TextBox looses focus
local function onFocusLost(enterPressed, inputObject)
    -- Check if TextBox lost focus because the user pressed "Enter"
    if enterPressed then
        if chatInput.Text ~= "" then
        -- Add the message to the GUI (no need to filter messages from the local player)
        addMessage(player, chatInput.Text)
        -- Send message to the server to get filtered and sent to other players
        chatMessageEvent:FireServer(chatInput.Text)
        -- Reset TextBox text
        chatInput.Text = "Press '/' or click here to chat"
        if game.Players.LocalPlayer:FindFirstChild("Chatting") then
            game.Players.LocalPlayer.Chatting:Destroy()
        end
        else
            chatInput.Text = "Press '/' or click here to chat"
        if game.Players.LocalPlayer:FindFirstChild("Chatting") then
            game.Players.LocalPlayer.Chatting:Destroy()
        end
        end
    elseif  inputObject.UserInputType == Enum.UserInputType.MouseButton1 then
        chatInput.Text = "Press '/' or click here to chat"
        if game.Players.LocalPlayer:FindFirstChild("Chatting") then
            game.Players.LocalPlayer.Chatting:Destroy()
        end
    end
end

-- Function when the player presses the slash key
local function onSlashPressed(actionName, inputState, inputObject)
    if inputState == Enum.UserInputState.End then
        -- If key up then capture focus in the TextBox so the user can start typing
        if game.Players.LocalPlayer:FindFirstChild("Chatting") then
            game.Players.LocalPlayer.Chatting:Destroy()
        end
        local Prev = Instance.new("StringValue",game.Players.LocalPlayer)
        Prev.Name = "Chatting"
        chatInput:CaptureFocus()
    end
end

-- Disable ROBLOX default chat
game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Chat, false)

 script.Parent.ChatFrame.MessageFrame.AutoSizeCanvas = true

-- Bind functions
chatMessageEvent.OnClientEvent:connect(addMessage)
chatInput.FocusLost:connect(onFocusLost)
ContextActionService:BindAction("Chatting", onSlashPressed, false, Enum.KeyCode.Slash)