All perfect praise be to Allah The Lord of The Worlds and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his familty and companion.

The Messenger of Allah (PBUH) said: "Whoever forgets a prayer, let him perform it when he remembers it." [Muslim]. As soon as you (Questioner) wake up, you are obliged to make up the missed Fajr prayer. And Allah Knows Best.