GA Flight Instructor with student reported an NMAC with an air carrier aircraft while training in a practice area near GUM airport. The air carrier was on final approach to GUM. The conflict required evasive action.

Narrative

We were training at the practice area that is class G with no transponder. Aircraft Y (Air Carrier) was coming in to final approach. We had traffic in sight and was watching them on our GPS; and also listing to Guam center. But Guam center did not have us on radar nor Aircraft Y had us in sight. I knew that Aircraft Y was descending; I decide to climb to avoid traffic. As we did that we came directly align with each other giving us about 4;000 feet horizontal distance; getting too close to each causing a near miss. It was VFR; but there was also clouds here and there.Having no transponder; clouds being visible; and me the pilot deciding not contacting Guam center for traffic advisory where the practice area is near the ILS path was the contributing factors.I should have contacted center for traffic advisory to help me; but also other aircraft. I also should have descended because we can never out climb an air carrier. Also; I know that the Aircraft Y will never go below the final approach fix altitude.