Questioner: With what should you end the first khutbah with on the Friday? Is it allowed to end with ordering people to seek forgiveness?
Shaikh: The khutbah on jummah, whether the first khutbah or the second, does not have specific structure. Holding fast to seeking forgiveness at the end of the khutbah is not a saheeh sunnah. It came in a weak hadith which is not allowed to act upon like a sunnah; however, if he does that sometimes then there is no harm due that entering into the general evidences. As for holding on to that like a necessary Sunnah, then it does not have an origin in the Sunnah. Yes.”
[Taken from: https://albanyimam.com/play.php?catsmktba=11555 ]
Faisal ibn Abdul Qaadir ibn Hassan