Place the trivet inside your Instant Pot liner. Add 1 cup of water to the bottom of the liner.
In a large, oven-safe bowl that fits inside your Instant Pot (like a Pyrex bowl), combine the cream cheese, heavy cream, chopped artichoke hearts, squeezed dry spinach, mozzarella cheese, Parmesan cheese, garlic powder, salt, and pepper. Stir until everything is well mixed.
Carefully place the bowl onto the trivet inside the Instant Pot.
Secure the lid and set the valve to Sealing.
Cook on High Pressure for 5 minutes.
When the cooking time finishes, perform a Quick Release of the pressure.
Carefully remove the bowl from the Instant Pot. Stir the dip mixture until it is smooth and creamy.
Preheat your oven broiler. Sprinkle the Monterey Jack cheese evenly over the top of the dip in the bowl.
Place the bowl under the broiler for 2 to 4 minutes, watching closely, until the cheese is melted and lightly browned.
Serve hot with tortilla chips, crackers, or bread.
Notes
Squeeze as much water as possible from the thawed spinach; excess water will thin the dip.
If you do not have an oven-safe bowl that fits, you can mix the dip in a separate pot after pressure cooking the cream cheese and liquids for 3 minutes, then stir in the remaining ingredients and heat on the Saute function until melted.
For a tangier flavor, substitute 1/4 cup of sour cream for 1/4 cup of the heavy cream.