In order to return to Azeroth from the Shadowlands, you must first obtain the quest "Abandoning the Shadowlands" from Adventurers' League Headquarters in Stormwind or Orgrimmar. Once you have this quest, head to the Dark Portal in the Blasted Lands and speak to Khadgar. He will send you on a quest to close the Dark Portal, which will take you to the Netherscape. After completing this quest, you will be able to return to Azeroth.
