I am going to reveal Keith L's secret to getting great abs, which he revealed about 3 years ago. The workout focuses on isometric exercises. These include exercises like planks, side planks, and renegade rows.

This is the abs workout below. You can do it 2-3 times per week:

Front Plank for 2 minutes
Rest 60 seconds
Side plank on right for 2 minutes
Side plank on left for 2 minutes
Rest 60 seconds
3 sets of Renegade rows for 5 reps per side

If you're a beginner you most likely won't be able to do the workout above. In order to make it easier, simply reduce the length of time you hold the plank from 2 minutes to around 30 seconds. Your goal with each workout should be to simply increase the amount of time you're holding the planks. As long as the time is going up, you're good to go. And for those who are unfamiliar with Renegade rows.

Now, Do You Want To Get Abs Like a Fighter?

I recommend you check out this fighter ab workout by Andrew Raposo. It reveals the unique style of training used by fighters.
See it here:
https://www.youtube.com/watch?v=QHbvWwTGt5I

In order to avoid the endless cycle of dieting and long hours of cardio to get your abs to show, we need to do a very specific type of training that fighters do which will also allow you to indulge in your favorite foods so that you can fully enjoy your lifestyle.

0-6 Pack Abs by Tyler Bramlett is also a great ab training program that users advanced exercise methods.
https://medium.com/fitness-reviews/my-honest-review-on-0-6-pack-abs-by-tyler-bramlett-and-dr-vegher-c12b2ab86a3

I think diet is the most important thing to reveal your abs