The imam remembers the prostration for forgetfulness after the closing salam; does he prostrate with the congregation or does he prostrate alone?

Question:
May Allah reward you with good and do you good. If the imam forgets a prostration at the end of the prayer and says the salam, and no one reminds him until after the salam, does everyone prostrate for forgetfulness, or does only the imam prostrate? May Allah reward you with good.

Answer:
If the meaning is that he forgot a prostration from the prostrations of the prayer, then if this prostration is the last thing in the final rak'ah, meaning it is from the final rak'ah which is followed by the tashahhud, he returns and performs the prostration, and performs what comes after it, then from the prostration and the tashahhud, then he says the salam, then he prostrates for forgetfulness after the salam, or he prostrates for forgetfulness before the salam.
As for if this prostration is from a rak'ah before the final one, and he has already said the salam from his prayer, then it is like leaving a complete rak'ah. He stands up and performs a complete rak'ah, then he prostrates for forgetfulness before the salam or after it. In this case, after the salam is better. Yes.