Answered by Shaykh Faraz Rabbani
What to do if the one leading the prayer is travelling, and you are resident. The Imam does 2rakatand you have to do 4. What do you recite?

Walaikum assalam,
According to the more correct opinion, the resident follower praying behind an imam who is a traveller does not recite anything at all in the third and fourth rakats. Not the Fatiha, or anything else. [Maraqi, Radd al-Muhtar]
Wassalam,
Faraz Rabbani.