It is recommended to pray two rak`ah for the sunnah of Fajr. And encouragement to pray them regularly, and to make them brief, and to persist in offering them, and clarifying what is recommended to recite therein Sahih Muslim 724 d
Translation
'A'isha reported that the Messenger of Allah (ﷺ) observed two rak'ahs of the dawn prayer and he shortened them (to the extent) that I (out of surprise) said
Did he recite in them Surah Fatiha (only)?