How can i change player's bubble chat text after player chats the word that changes your text in bubble chat?

You can write your topic however you want, but you need to answer these questions:

  1. What do you want to achieve? Chat Changing

  2. What is the issue? Nothing

  3. What solutions have you tried so far? I use Chat:Chat()

After that, you should include more details if you have any. Try to make your topic as descriptive as possible, so that it’s easier for people to help you!

local Chat = game:GetService("Chat")

game.Players.PlayerAdded:Connect(function(player)
	local character = player.Character or player.CharacterAdded:Wait()
	player.Chatted:Connect(function(message)
		if message == "Hi!" then
			Chat:Chat(character.Head,"Hello!",Enum.ChatColor.Blue)
		end
	end)
end)

Please do not ask people to write entire scripts or design entire systems for you. If you can’t answer the three questions above, you should probably pick a different category.

https://developer.roblox.com/en-us/api-reference/function/Chat/Chat

The 3rd parameter represents the chat’s color.