Sauté Garlic. Set your Instant Pot to "Sauté" mode, add a bit of olive oil, and sauté the minced garlic until fragrant.
Combine Ingredients. Add the chopped artichoke hearts, mayonnaise, Parmesan cheese, mozzarella cheese, cream cheese, salt, black pepper, and a dash of lemon juice to the Instant Pot. Stir to combine.
Pressure Cook. Close the Instant Pot lid and set it to "Pressure Cook" on high for a few minutes until the cheeses are fully melted and the dip is heated through. Quickly release the pressure in the Pot.
Garnish. Once cooked, serve the artichoke dip in a serving dish. Garnish with chopped green onions and a sprinkle of crushed red pepper flakes for a touch of heat. Broil for 2-3 minutes (optional) for a golden brown top.