Set your Instant Pot to the saute setting
Add olive oil, onions, garlic, celery, and carrots to the Instant Pot. Saute until the onions and celery are transparent.
Add green beans, zucchini, tomato paste, diced tomatoes, Italian seasoning, bay leaf, and vegetable broth to your Instant Pot.
Close Instant Pot Lid, and cook on high pressure for 15 minutes. Let naturally release.
While the soup is cooking, cook your pasta shells al dente on the stove top.
Once your pressure has released, open your Instant Pot lid.
Drain kidney beans, and add to the soup.
Serve up your soup. Let your guests add their desired amount of beans into their bowl, and then add soup.