Thank you very much for your question. It is our pleasure to answer it.

In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright.

Dear brother, what is to be said in sujud sahw is the same as what is to be said in the sujud of prayer, which is to say Subhana Rabbi al-Alaa (Glory be to my Lord Most High) or other tasbihat which are reported as being sunnah to say in sujud.