Fakename Mod (1.18.2, 1.6.5) allows you to change your in-game nickname for another. This mod can be used to fool your friends by making them think that a famous YouTuber has joined the server. You can also change your chat name and death messages, but your skin is not affected. You will need to change your skin if you want it to appear that you are a YouTuber.
Your name is not permanently changed by the mod. It is only available to world/server-specific users. This is not hackable. The mod must be installed on the server.