Google is our friend.
https://www.hippressurecooking.com/pressure-cooker-oatmeal-how-to/
This is one of many sites with useful information. Pressure Cookers and Instant Pots have come a long way. Depending on the situation , your needs, perhaps one does the job, then perhaps one of each is required.  Regardless, they are great inventions much like the Oral B Electric Toothbrushes.