How to make LocalPlayer chat and bypass FE?

I am making an custom chat ui and it has this in a LocalScript

local m = game.Players.LocalPlayer:GetMouse()
m.KeyDown:connect(function(k)
	if k == '/' then
		game.Players.LocalPlayer.PlayerGui.ChatUI.Frame.Frame.TextBox:CaptureFocus()
		game.Players.LocalPlayer.PlayerGui.ChatUI.Frame.Frame.TextBox.typing.Value = true
	elseif k == '\r' or k == '\n' then
		if game.Players.LocalPlayer.PlayerGui.ChatUI.Frame.Frame.TextBox.typing.Value == true then
			game.Players.LocalPlayer:Chat(game.Players.LocalPlayer.PlayerGui.ChatUI.Frame.Frame.TextBox.Text) -- This line doesn't work
			game.Players.LocalPlayer.PlayerGui.ChatUI.Frame.Frame.TextBox.typing.Value = false
			game.Players.LocalPlayer.PlayerGui.ChatUI.Frame.Frame.TextBox.Text = "Click here or press '/' to chat"
		end
	end
end)

Now... how do I make the game.Players.LocalPlayer:Chat() work?

In an normal Script I have:

local chatstorage = game.Workspace.ChatStorage

game.Players.PlayerAdded:connect(function(plr)
	plr.Chatted:connect(function(msg)
		local chat = Instance.new('Folder', chatstorage)
		
		local msgVal = Instance.new('StringValue', chat)
		msgVal.Name = 'Message'
		msgVal.Value = plr.Name..': '..msg
		
		local colVal = Instance.new('Color3Value', chat)
		colVal.Name = 'Color'
		colVal.Value = Color3.new(math.random(255)/255,math.random(255)/255,math.random(255)/255)
	end)
end)

but it won't fire the plr.Chatted when I use the game.Players.LocalPlayer:Chat() in a LocalScript. How to fix this?

game.Players.LocalPlayer:Chat() can only be used by plugins and core scripts I believe.