Set the Instant Pot to sauté mode and heat the olive oil. Add the onion, garlic, and ginger, then cook for 2 minutes until softened.
Stir in the red curry paste and cook for 1 minute more to release its aroma.
Pour in the chicken broth and add the sliced red bell pepper. Cancel sauté mode, secure the lid, and set to manual high pressure for 3 minutes.
Quick release the pressure once the timer ends. Stir in the coconut milk, shrimp, fish sauce, and lime juice.
Set the Instant Pot back to sauté and cook for 3 to 4 minutes until the shrimp turn pink and opaque.
Ladle the soup into bowls and top with chopped cilantro before serving.