Is a traveler who is in a non-Muslim country for medical treatment sinful if he prays in his home due to his inability to go to the mosque?

Congregational prayer is obligatory for adult men, and a mosque is not a condition for it. So, if you pray in your home with your brothers, you have fulfilled your obligation. However, if you do not find anyone to pray with in congregation and you hear the call to prayer without a loudspeaker, then it is obligatory for you to go to the mosque. But if you are far away and do not hear the call, or if you are sick, then congregational prayer is not obligatory for you. Nevertheless, enduring hardship to go to the mosque holds great virtue.