Unfortunately we didn't add every cooking method when we started EYB and it is always difficult to add new recipe categories when we have 2.3 million recipes already indexed. The cooking methods we do have are Grills/BBQ, Stir-fries plus lots of Dish types listed in the filters under Recipe types / Dish types.
The way I suggest finding Instant Pot recipes is to search by those words in speech marks as that will show any recipes in your cookbooks that have Instant Pot in the title of the book, as IP books always do. And if you are looking at Online Recipes, they often have Instant Pot in the title too.