Making Up Fajr
Sunnah or Nafl prayer is not obligatory to repeat if missed. It is additional prayer. You can say you prayer until the last minute. The prophet says that the one who finds on rakat in time, he got his prayer. It means he can complete the rest of the prayer even if the sun rises or sets. Around sun rise and set Dua and resting or reciting of Qur’an is allowed. Only a new prayer is forbidden.