Answered by Shaykh Nazim Mangera
I have had to work late and cannot get into bed until late, and have had trouble getting up and concentrating for the Fajr prayer. Any suggestions? If I can’t make Fajr because of work, then can I make it later?

Assalamu Alaikum,
All the prayers must be performed at their prescribed times under normal conditions. If you do miss them, you will have to [repent and] make them up later. What you could also try to do is give others advice about performing Fajr prayers and if they act upon your advice, you will be getting the reward of them praying as well.
Please view the following link:
Unable to get up for Fajr: is it due to the workings of Shaytan?
Allah knows best
Sincerely,
Nazim Mangera