This quest is not available in game.
Report to Krug Skullsplit at the Orgrimmar Legion post in front of Hive'Regal. Prepare your Unsigned Field Duty Papers, obtain Signed Field Duty Papers and bring them to Windcaller Kaldon in Cenarion Hold.
Note: Healing or casting beneficial spells on a member of the Orgrimmar Legion will flag you for PvP.
Greetings, <name>. Before I assign you to more involved tasks in the war, you'll need to do your share of field duty.
You will find Captain Skullsplit's Orgrimmar Legion outside Hive'Regal.
Report to him and come back to me with proof of your field service. I shall have a more advanced assignment ready for you.
Oh, please do your best to stay away from the Ironforge Brigade. Tensions are high among our Alliance and Horde volunteers.