Using the sauté function on your Instant Pot, brown the ground beef.
Halfway through browning, add the diced peppers and onions. A few minutes later, add the garlic.
When beef is browned and peppers and onions are softened, add the rest of the ingredients.
Add lid and set Instant Pot to 50 minutes on manual.
Allow for natural pressure release (I've done quick release when in a hurry, and it's fine in a pinch.)
Serve with your favourite toppings, and enjoy!
Notes
Lately I've been replacing one of the cans of diced tomatoes for a can of plain tomato sauce (just pureed tomato, no other ingredients). My kids prefer it with less chunky tomatoes, but it totally works fine either way.