Instructions
Start "World of Warcraft." Sign into your battle.net account on the World of Warcraft login screen. Enter your authenticator code if you have an authenticator.
Select your "World of Warcraft" character on the character selection screen and click "Enter World."
Press "Enter" on your keyboard once the game loads. The chat text box will appear. Type "/sleep" without the quotation marks. A message will appear in the chat box that says "You fall asleep. Zzzzzz." Your character will lie down in a sleeping position.