Spray the Instant Pot bowl with non-stick spray and add the ground beef. Turn the Instant Pot to the Sauté function, and cook until the meat is browned all over - stirring regularly. Cancel the cook function and drain the excess grease from the bowl.

Add the tomato sauce, low carb ketchup, red bell pepper, Worcestershire sauce, dry mustard powder, onion powder, salt and pepper. Stir well to mix.

Seal the lid and switch the Instant Pot to manual, low pressure. Set the time for 5 minutes with the steam release valve closed.

After the cooking time has finished, quick release the steam, and transfer the low carb sloppy joes mix to a bowl. Serve with low carb buns.