Rinse pork belly. Set trivet inside pot with 2 c water inside. Set pork on trivet and close lid and steam valve. Set to high pressure for 65 minutes if left whole. (if cut into 1" cubes in vegetable steamer basket set to 19 minutes + 15 minute natural release)
Allow steam to naturally release once done. Remove from pot and pat dry. Coat the fat with salt. Poke top surface with holes with a knife.
Place on a plate lightly covered with plastic wrap. Keep in the fridge overnight. Uncover and scrape as much salt off as possible.
Preheat air fryer to 200 degrees, spray basket and air fry for 40 minutes. Then turn up to 325 F and cook an additional 10-20 minutes to brown the top crispy as you'd like. (if you're cooking it cubed cook at 400 degrees for 6-8 minutes shaking basket halfway through)
Remove and let sit for 10 minutes before slicing and enjoying.