1.Knee Raises to Chest
A good exercise to burn subcutaneous fat to reveal your abs is knee raises to chest (before that, you don't even need to lift straight legs) - namely, bent knees to chest... not lowering all the way down to prevent the muscles from relaxing. According to the method:
- raise to the left side
- raise knees towards yourself
- raise to the right side
and repeat from the beginning. And keep doing it until either your abs give out or your arms get too tired to hold on.
2. And this video for doing it at home on the floor:
I just took a dumbbell over my head for some exercises to make them more challenging. And it's important to make sure to perform everything with quality, without slack, and with full amplitude.

3. if you have a roller, performing body lowering to the floor, standing on knees - the press is also loaded. (It's even more loaded on straight legs, but it's a very difficult exercise, you won't be able to do it without preparation). I call it "riding the roller for arms, standing on knees".

All of this together - in a couple of weeks will definitely make your abs defined.
MAIN THING: to dry out the muscles and make them defined it's about the number of repetitions.