Place metal rack in the Instant Pot and put ribs on top of the rack.
Sprinkle ribs with salt and pepper.
Add barbecue sauce and Coca Cola.
Place lid on the Instant Pot and make sure the vent is set to "sealing." Turn on pressure cooker "meat" mode for 20 minutes.
While the ribs are cooking, turn your oven broiler on "high."
When the cook time is up, do a quick pressure release. Remove the ribs from the cooker and place on a baking sheet or in a baking dish.
Brush ribs with a fresh coating of barbecue sauce.
Place in oven and cook for 5 minutes under the broiler set to "high," just until the sauce is caramelized on top.