This quest can be completed after defeating the darkspawn waves during the main quest The Descent. After establishing the first Inquisition Camp, inspect the Expedition Table and select The Deep Roads card on the left. You will now be able to select the operation Deep Roads Expeditions: Legion Camp Improvements, thereby creating improvements for the first inquisition camp that you encounter in the Deep Roads. When the operation is complete and you have collected the reward, the quest will complete.