First, get the stem out of the pumpkin.
Put the steamer basket into the Instant Pot.
Add in the cup of water and put the pumpkin on top of the steamer basket.
Close the lid on the Instant Pot and seal the valve.
Cook on "Manual" high pressure for 13 minutes.
Once that is done, allow for a natural release of pressure.
Remove the pumpkin, and then grab a cutting board to put the pumpkin on.
Allow it to cool for 10 minutes and then slice it in half. Remove all of the seeds, all inner goop, and also peel the skin off.
Use an immersion blender or food processor to blend up the pumpkin. You can add a little more water if needed, about a tablespoon.
Store in jars until you are ready to use.