Rinse mung beans well and add to Instant Pot. Add 10 cups of water or up until the ½ mark on the Instant Pot.
Close and lock the Instant Pot lid. Press 'Bean/Chili options" and set it to "High Pressure." Set the timer for 30 minutes.
When done, the Instant Pot will read 'Keep Warm.' You can let it naturally release, which may take another 25-30 minutes. You can also manually release the pressure. Follow the instructions of your Instant Pot to do so safely.
If you'd like the soup to be thicker, select the 'Sauté' option. Allow the liquid to come to a boil and end when the soup reaches a consistency to your liking.
Stir in rock sugar or sweetener of choice. Drink warm as is or allow it to cool and store in the fridge in an airtight container to drink chilled.