What is the ruling on the prostration for forgetfulness and its places?

In his second question, he says: What is the prostration for forgetfulness, when is it required, and how is it performed? Is it before the closing salam or after it? And how do I act if I do not know whether I prostrated two times or one, or whether I recited the tashahhud before the salutation upon the Prophet (peace and blessings be upon him) or not? Most of these situations are based on suspicion?
Answer: The prostration for forgetfulness is obligatory for what would invalidate the prayer if done intentionally. If one does something or leaves something out—forgetfully—that would invalidate the prayer if done intentionally, he must perform the prostration for forgetfulness; because it completes the prayer, and the Prophet (peace and blessings be upon him) commanded the prostration for forgetfulness to complete the prayer. So, for example, if one forgets the tasbih in ruku' and sujud, it is obligatory for him to perform the prostration for forgetfulness according to the correct opinion of the scholars; because the correct view is that these tasbihs are obligatory, at least once.. at least one tasbih. Likewise, if one forgets the first tashahhud, it is obligatory for him to perform the prostration for forgetfulness according to the most correct opinion of the scholars, as the Prophet (peace and blessings be upon him) did.
Likewise, if, for example, one forgets ruku' and prostrates, then returns and performs ruku', he completes his prayer and prostrates for forgetfulness. Likewise, if one forgets a rak'ah and says the salam, or two rak'ahs and says the salam, then he remembers or is reminded, he completes his prayer and prostrates for forgetfulness as well, and this is obligatory. The rule is: anything that would invalidate the prayer if done intentionally, if done forgetfully, requires the prostration for forgetfulness. He has a choice: if he wishes, he does it before the salam, and if he wishes, he does it after the salam. When the tashahhud and supplication are completed, it is prescribed for him to prostrate for forgetfulness before he says the salam. If he delays it until after the salam, that is permissible. However, the better option in most types of forgetfulness is to do it before the salam. It is better to do it before the salam. If he says the salam while missing two rak'ahs or more, if he says the salam while missing three in the Dhuhr, 'Asr, or 'Isha' prayer, or while missing two in the Maghrib prayer, or while missing one in the Fajr or Jumu'ah prayer, and then he is reminded, he stands up and completes the prayer, and he makes his prostration after the salam, as the Prophet (peace and blessings be upon him) did. This is the better option. If he says the salam while missing ..... or more, then he is reminded or remembers and completes his prayer, his prostration is after the salam. He says the salam, then prostrates for forgetfulness two times, then says the salam again. This is the better option when his forgetfulness is by saying the salam while missing something. The better option is to do it after the salam. As for the other types of forgetfulness, the principle is that it is before the salam, such as leaving out the first tashahhud, leaving out the tasbih in ruku' or sujud, or adding a rak'ah to the prayer and then remembering and sitting. He completes the prayer and then prostrates for forgetfulness before he says the salam. If he prostrates after the salam, there is no harm.
Likewise, what is done after the salam is when one acts on the preponderance of his suspicion, if he acts on the preponderance of his suspicion. For example, if it is preponderant in his mind that he completed the prayer, and he is in doubt between three or four, and it is preponderant in his mind that it was four, and he builds his prayer on this and completes it as four, he says the salam, then prostrates for forgetfulness after that, then says the salam, because he built his prayer on the preponderance of his suspicion. Likewise, if he is in doubt whether he prostrated once or twice, he counts it as one prostration and performs the second prostration, and prostrates for forgetfulness before the salam. For example, if he prostrated once and is in doubt whether it was the first or the second, he counts it as the first and performs the second prostration until he is certain of his prayer. Then, when he completes the prayer, he prostrates for forgetfulness two times. This is what is prescribed. If he delays the prostration for forgetfulness until after the salam, there is no blame on him. However, in two cases, it is better after the salam: one of the cases is if he says the salam while missing a rak'ah or more, then he is reminded and remembers, he completes his prayer and prostrates for forgetfulness after the salam. The second case is if he builds his prayer on the preponderance of his suspicion, not on certainty, but on the preponderance of suspicion. It is permissible for him according to the correct view. If he builds his prayer on the preponderance of his suspicion, he completes the prayer and says the salam, then prostrates for forgetfulness, then says the salam. Other than this, the prostration is before the salam. This is the better option, according to the apparent meaning of the Sunnah.