Is one who misses the Friday Prayer and prays it as Dhuhr at home sinful, due to the closure of mosques in the foreign country in which he resides because of the Coronavirus pandemic?

If Friday prayer is not established in your country due to an epidemic, then there is no sin upon you, and you must pray Dhuhr instead, because Allah does not burden a soul beyond its capacity. Continue to be righteous, safeguard your prayers, and take the righteous as friends to help you obey Allah.