The Messenger of Allah ﷺ used to recite in teh first rak'ah of Fajr "Say: We believe in Allah and that which has been sent down to us" to the end verse, and in the second rak'ah, "We believe in Allah, and bear witness that we are Muslims."  

أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَقْرَأُ فِي رَكْعَتَىِ الْفَجْرِ فِي الأُولَى مِنْهُمَا الآيَةَ الَّتِي فِي الْبَقَرَةِ { قُولُوا آمَنَّا بِاللَّهِ وَمَا أُنْزِلَ إِلَيْنَا } إِلَى آخِرِ الآيَةِ وَفِي الأُخْرَى { آمَنَّا بِاللَّهِ وَاشْهَدْ بِأَنَّا مُسْلِمُونَ }