How to Fall Asleep Fast!?

I have a sleep test and I really need to get to sleep right now so that I can sleep for four hours and the sleep test can be accurate

Suggestion:

i sometimes when i cant sleep i just imagine stuff. like what if i went to an amusement park with my friends? i think about all the details. like dreaming but you're woke. and if you just close your eyes its easier to fall asleep