Heat the olive oil in the Instant Pot on sauté mode, medium. (Higher heat may burn.)
Add the diced bell peppers, onions, and garlic to the hot oil. Let everything simmer for about two minutes, stirring occasionally.
Add the ground turkey and break it down into smaller chunks using a spatula or a large spoon. When the turkey is broken down into crumbles and half cooked, cancel the sauté function.
Add salt, pepper, chili powder, smoked paprika, Worcestershire sauce, and Dijon mustard to the meat, and stir until it's well mixed.
Add water and stir again. Then, add the ketchup and tomato paste to the Instant Pot, but don't stir it. The sugar in the ketchup could trigger the burn notice, so you want to avoid that. You can stir it in the end.
Secure the lid on the Instant Pot and set the valve to Sealing; cook on high pressure for 8 minutes.
When the Instant Pot beeps, do a quick release and open the lid when it's safe to do so. Stir the contents well to mix in the ketchup and tomato paste, then mix in the scallions.
Serve with fresh brioche buns.