Wash the exterior of your pie pumpkin or sugar pumpkin (Make sure your pumpkin fits inside of your pot without passing the top of the rim.
Cut off or break off as much of the stem as you can (be careful if using a knife)
Place your metal trivet at the bottom of your instant pot insert
Add in one and half cups of water to the bottom
Place your pumpkin onto of the metal trivet
Add your lid and close it. Set the gasket to "sealing" mode
Press the "Manual" mode and adjust the time to 15 minutes
When finished, allow the Instant Pot to do a Natural Release (basically let it sit idle when the 15 minutes ends until the pin releases)
Allow to cool for at least 15 minutes and then carefully remove the pumpkin from the Instant Pot
Process the cooked pumpkin in your preferred method. An easy way is to cut a hole out of the top and scoop out the seeds to limit the mess
Mash the pumpkin flesh with a fork if you want a thicker texture or pop into your blender and blend away until you have the desired consistency