How do we do sajda sahu?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
After reciting attahiyyatu in the last qa'da, one should give salam on his right side and go into sajda and read 3 tasbeehs. After sitting in jalsa, one should go back into sajda, then sit again and read attahiyyatu, durood Ibrahim, dua, and then give both salams.
Only Allah knows best
Written by Alimah Sumeyye Sofu
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 al-Hidayah p.329 v1 Maktabatul Bushra