In the Instant Pot, heat the olive oil over Sauté mode. Add the ground beef and cook until browned, breaking it up with a spatula. Add the onion and garlic and cook until softened, about 5 minutes. Stir in the chili powder, cumin, and cayenne pepper. Cook for 1 minute more. Add the black beans, kidney beans, diced tomatoes, beef broth, salt, and pepper. Close the lid and seal the valve. Cook on High Pressure for 20 minutes. Let the pressure release naturally for 10 minutes, then quick release any remaining pressure. Serve with your favorite toppings, such as shredded cheese, sour cream, and avocado.