None. No abs to flaunt. But my sons do have abs (not 6pack though) that they carefully maintain in our set-up little gym in the garage. Yoga, walks, stepper-exercises, dance, zumba are fine too.
You may stay active even in small areas by moving around or standing still. If you have a call, get up and move around your house rather than sitting still.
There are many calisthenic workouts that can be done while self-isolating. Some good calisthenic workouts to practice during lockdown include weightlifts, planks, Swiss ball exercises, and weightlifts. Stay safe and enjoy your isolation while maintaining your range of motion.