There are many different ways to make hard boiled eggs in the Instant Pot. Here's the method that works best for me.
Put 1 1/2 cups of cold water and the trivet in the pot. Pile as many eggs as you want on the trivet. Go ahead and stack 'em up. I've done 18 at once in my 6-quart. And it's perfectly okay if eggs touch the side of the pot.
Close the lid, set the valve to Sealing and press the Pressure Cook (or Manual) button. Use the + or - button to get to 4. When it beeps that it's done, leave it for 4 more minutes.
Flip the valve from Sealing to Venting to release the remaining pressure. When the pin drops, open the pot and put the eggs in an ice water bath or under cold running water for 5 minutes.
This is the 4/4/5 method. You can switch it to 5/5/5 if you like. People usually find the times they love best and stick with it.