Does saying “Allahumma salli ala Muhammad” after reciting the tashahhud in the first sitting of obligatory prayers…

In prayer, if a pillar is delayed or repeated by mistake, or if a wajib act is omitted or delayed, it is obligatory to perform the prostration of forgetfulness (sujood as-sahw) to compensate for the deficiency. In obligatory prayers, if someone says “Allahumma salli ala Muhammad” after reciting the tashahhud in the first sitting—when one should stand up—according to Imam Abu Hanifa, they have delayed the obligatory standing and must perform sujood as-sahw; thus, their prayer is completed. According to Imam Abu Yusuf and Imam Muhammad, sujood as-sahw is not required in this case (Kâsânî, Bedâi‘, 1/164).

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu