How to wake up for Fajr
Try to get sleep as soon as you can after you finish your isha prayer and plan for that in advance sometimes it takes us to really plan for that and make sure things are out of the way.
In relation to screen time, time on your mobile phone, laptop, etc, research has shown that what we do right up until the point that we fall asleep will affect the quality of our sleep.
When someone sleeps with that state of mind ( prophetic supplications ) likely allows you to wake up quickly because you're conscious of Allah, sleeping conscious of Allah hopefully, you wake up with that consciousness too that will encourage you to get up quickly and respond to your alarm.
Keep the alarm away from you, don't put your alarm by your bedside because it's tempting to just switch it off and hit the snooze button then go back to sleep. Keep the alarm someplace where you need to take a few steps to turn it off.