If forgetting to recite Surah Al-Fatihah, what one should do

Q 1: Is it permissible to offer Salah (Prayer) without reciting Surah Al-Fatihah due to forgetting it and only remembering about it after saying the Taslim (salutation of peace ending the Prayer) or should I offer the Salah again? A: If someone forgets to recite Surah Al-Fatihah in any Rak‘ah (unit of Prayer), whether while being an Imam (the one who leads congregational Prayer) or offering the Salah individually, and remembers while they are still praying, before starting the next Rak‘ah, they should go back and recite it and then perform the Ruku‘ (bowing) and then the Sujud (prostration). If they do not remember until after starting the next Rak‘ah, then the Rak‘ah in which they forgot to recite Al-Fatihah is Batil (null and void) and the Rak‘ah following it will replace it. If they do not remember until after saying the Taslim, they should rise and offer a full Rak‘ah and then perform Sujud-ul-Sahw (Prostration of Forgetfulness), in all these cases, before saying the Taslim. If they only remember a long time after they had said the Taslim, then they should repeat the whole Salah. If they are Ma’mums (persons being led by an Imam in Prayer), the Imam bears the responsibility, whether this was done out of ignorance of the ruling or out of forgetfulness. (Part No. 6; Page No. 7

A: If someone forgets to recite Surah Al-Fatihah in any Rak‘ah (unit of Prayer), whether while being an Imam (the one who leads congregational Prayer) or offering the Salah individually, and remembers while they are still praying, before starting the next Rak‘ah, they should go back and recite it and then perform the Ruku‘ (bowing) and then the Sujud (prostration). If they do not remember until after starting the next Rak‘ah, then the Rak‘ah in which they forgot to recite Al-Fatihah is Batil (null and void) and the Rak‘ah following it will replace it. If they do not remember until after saying the Taslim, they should rise and offer a full Rak‘ah and then perform Sujud-ul-Sahw (Prostration of Forgetfulness), in all these cases, before saying the Taslim. If they only remember a long time after they had said the Taslim, then they should repeat the whole Salah. If they are Ma’mums (persons being led by an Imam in Prayer), the Imam bears the responsibility, whether this was done out of ignorance of the ruling or out of forgetfulness. (Part No. 6; Page No. 7) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.