Is the Adhan obligatory before prayer for an individual or a congregation in non-Muslim lands when it is not heard, or is it merely recommended and not a condition?

The preponderant view is that the Adhan (call to prayer) and Iqamah (second call to prayer) for an individual praying alone are mustahab (recommended), and their prayer is valid without them. As for the mosque's Adhan for the congregation, it is fard kifayah (a collective obligation). It is necessary to strive to build a mosque and establish the ritual of the Adhan and congregational prayer, based on the Prophet's (peace be upon him) saying: "There are no three people in a village or in a desert who do not establish prayer among them except that Satan has taken control over them. So, adhere to the congregation, for indeed the wolf eats the isolated sheep." If there is a nearby mosque where the Adhan is not called, and there is no one else to call it besides the questioner, then calling the Adhan becomes wajib (obligatory) upon him.