Pierce the potatoes in several places with a fork.
Put water and potatoes in the Instant Pot (you can use the trivet or put potatoes directly in the water).
Close the lid of the Instant Pot and turn the valve to a Sealing position. Press the "Pressure Cook" or "Manual" button and set the time to 15 minutes for medium potatoes or 20 minutes for large potatoes.
When it's done cooking, let the pressure release naturally for 10 minutes, then quick release (QR) the remaining steam.
Remove baked potatoes from the Instant Pot and serve with salt, pepper and your favorite toppings.
Video
Notes
You can cook as many potatoes as you'd like, as long as they fit below the "Max Fill" line of the Instant Pot. The cooking time and amount of water remain the same.