Israelis residing abroad during the second day of the festival

I sent a question about a yeshiva student who flew for three months to a yeshiva in the United States, whether he needs to observe the second day of the festival, and about tefillin. Now I want to ask a more specific question: what is the halacha inside a private apartment that is only for the boys? Do they need to observe there as well? And what about Simchat Torah? What do we do in prayers on the first and second day? Thank you very much and a good year.

Hello and a good year. As I wrote in the previous response, if a person is in an area where there are Jews, he needs to observe the second day of the festival, both in private and in public. The only exceptions are laying tefillin and praying the quiet amida prayer. In these two, a resident of Israel should act as on a weekday, but discreetly. Only if the boys are in a place where there are no Jews, do they not need to observe the second day of the festival.

Shulchan Aruch, Section Orach Chaim, chapter 496, §3