Lock lid in place and close pressure release valve. Select Pressure Cook function and cook for 15 minutes. Turn off Instant Pot and quick-release pressure. Carefully remove lid, allowing steam to escape away from you.
Stir shrimp into tomato mixture, cover, and let sit until opaque throughout, 5 to 7 minutes. Stir in olives and parsley and season with salt and pepper to taste. Sprinkle individual portions with scallions and drizzle with extra oil before serving.
Recipe Notes
*Pressure Cook and Manual buttons are interchangeable