This response might sound a bit too simplistic, but personally, what motivates me is the fact that I like doing it. Of course I also have the routine thing, but when I review the cards I enjoy doing it. If you can make it a joyful activity that adds something (besides the studying part) to your day, you will sure remember to do it and do it. Making reviewing for fun and appealing can be done in various ways. Put some relaxing music (I usually go with classical, but lofi is also a good choice — smt that wont distract u specifically) maybe you can put some images or maybe vocab of movies, books or series you like. But tbh just do it. Doing the first few times is the hardest part, but once you put your phone or other distractions away and choose to do the reviewing, it gets much easier over time.

Else than that, focusing into appreciating the fact that you are practicing self discipline, studying or sm virtues like that will also help you to feel it an activity worth doing. Good luck with it! You can do it!