Add the beef broth,salt, pepper and garlic to the inner pot of a 6- to 8-quart Instant Pot.
Place the brisket on top of the mixture with fat side up.
Sprinkle the corned beef with the pickling spices that came with the corned beef.
Close and lock the lid. Set valve to sealing.
Select MANUAL toggle to HIGH and set the time for 70 minutes.
When the cooking time is complete, allow the Instant Pot to do a natural release.
Remove the corned beef from the Instant Pot to rest, covered.
Place the potatoes, carrots, onion & cabbage into the insert of the Instant Pot in the remaining juices.
Close & lock lid.
Select MANUAL setting, toggle to HIGH and set the time for 5 minutes.
When finished cooking, quick release the pressure.
Since the corned beef & serve with the vegetables.