Season the pork. Combine salt, orange zest, cumin, ground chile, epazote, and black pepper in a small bowl. Season all sides of the pork shoulder with the salt mixture. 

Sauté the onions. Add lard to the Instant Pot and select saute. Cook on Hi and set timer for 5 minutes. Once lard is melted add onions and saute, stirring occasionally. 

Pressure cook the pork. Add pork and close with the Instant Pot Pressure Cooker lid. Set the Pressure Cook setting on Hi for 1 hour 15 minutes. It will take a minute for the Instant Pot to set the pressure, then it will begin to cook and the timer will start. 

Release pressure. Let pressure release on its own slowly (or manually release the pressure if you're in a hurry). Set a strainer over a heat-proof bowl and strain out meat and onions saving the cooking liquid. Once pork is cool enough to handle, shred and return to the Instant Pot. 

Air-fry the carnitas. Place Air Fryer lid on top and set to Air Fry at 400°F for 12 minutes. The Instant Pot will ring halfway through and notify you to turn the carnitas. Remove the lid and set it on the provided base—careful the bottom of the lid is hot. Toss them around with a pair of tongs to get more edges nice and crisp. If after 12 minutes they are not crisp enough set the time for 3 more minutes or until done to your liking. 

Stir in reserved cooking liquid. Add a 1/2 cup or so of the cooking liquid back into the carnitas to make them nice and juicy. Drizzle the apple cider vinegar over the meat and toss to combine with the tongs.

Serve with warm tortillas. Serve immediately with warm tortillas, chopped onions, cilantro, or your favorite garnishes. Save any remaining cooking liquid for later to reheat the carnitas or use as a broth for soup.