Did the Prophet (peace and blessings be upon him) perform Qunut for a month in all prescribed prayers and in the Friday prayer when a calamity befell his Companions, and is it permissible for us to perform Qunut in the Friday prayer when a calamity befalls?

It has been authentically established that the Prophet, peace and blessings be upon him, performed qunut for a month in all five prayers, supplicating against the tribes that betrayed seventy of his companions. Therefore, qunut is prescribed during calamities (nawazil) to supplicate for the believers and against the disbelievers in all prayers, and it is a confirmed Sunnah. As for qunut in the Friday prayer, scholars have differed concerning it, and the majority of them are of the opinion that it is not prescribed, considering the supplication in the khutbah (sermon) sufficient, and it has not been reported that the Prophet, peace and blessings be upon him, performed qunut in it.