There is no expiation except to pray the same

Bismillah Walhamdulillah Was Salaatu Was Salaam 'ala Rasulillah

As-Salaam Alaikum Wa-Rahmatullahi Wa-Barakatuhu

Narrated Anas (Radi-Allahu 'anhu):

The Prophet (Sallallahu 'Alaihi Wa Sallam) said, "If anyone forgets a prayer he should pray that prayer when he remembers it. There is no
expiation except to pray the same." Then he recited: "Establish prayer for
My (i.e. Allah's) remembrance." (20.14).

Bukhari Vol. 1 : No. 571