What is the ruling on residing in a country where Friday prayers are not established and mosques are closed due to an epidemic, knowing the difficulty of returning to one's homeland and the unavailability of similar job opportunities?

There is no harm for your husband in residing in a country where Jumu'ah (Friday prayer) is not performed due to the pandemic, and he is not obligated to move from it. He should, however, be diligent in performing congregational prayers in his home or workplace.