Set Instant Pot to Sauté function and pour in oil. Cook onion, stirring occasionally, until softened, about 5 minutes. Stir in garlic and cook, stirring, until fragrant, about 1 minute more. Add tomato paste and stir to combine. Add beef and cook, breaking meat up with a wooden spoon, until no longer pink, about 7 minutes. Drain fat, if necessary.
Return insert to Instant Pot and add black beans, tomatoes, kidney beans, chili powder, oregano, cumin, and cayenne; season with salt and black pepper. Lock lid and set to Pressure Cook on High for 14 minutes.
Follow manufacturer’s instructions for a slow release, then remove lid.
Divide chili among bowls. Serve with desired toppings.
