Does an Imam's prayer alone in the mosque due to the absence of worshippers count as a congregational prayer, and what should he do?

The prayer of an individual alone is not considered a congregational prayer; rather, a congregation is formed by two or more people. If the place is a prayer room (musalla) and not a dedicated mosque (masjid), there is no harm in closing it and praying in another mosque to attain the reward of congregational prayer, because a musalla does not take the ruling of a mosque. However, if the place is a dedicated mosque, it is not permissible to close it. If the resident Imam prays alone in it due to the absence of other worshippers, he will attain the reward of congregational prayer, and he is not obligated to seek another congregation in a different mosque.