Put water and whole beets in your Instant Pot. Close the lid and turn the valve to a Sealing position.
Press the "Pressure Cook" or "Manual" button and set the time for 20 minutes (if your beets are larger then 3 inches in diameter, set the time for 30 minutes).
When the Instant Pot is done cooking, quick release (QR) the steam.
Remove the beets from the Instant Pot and peel them. Slice the beets, sprinkle with salt and pepper to taste and serve.
Video
Notes
You can use 1 cup of water and same cooking time for any amount of beets.