When a recipe says natural release (NR) for 10 minutes, they are signalling, that is when you can do a quick release of any remaining pressure. That extra 10 minutes is necessary because it adds more cooking time.
If you’re not in a hurry, just let the Instant Pot release on its own. Sometime, this can take up to 40 minutes because it’s dependent on how long it takes for the steam inside the pot to cool down and slowly release through the valve plus cool down from the pressure-causing steam to condensation.
If you want to speed this up, put cold wet clothes on the metal parts of the lid. Putting the cold wet clothes on the metal part of the lid helps the heat inside the pot to transfer outside of the pot quicker. As the water evaporates, the energy is being transferred, steam is turning to condensation, decreasing the pressure until all is released.