In a large bowl, using your hands or a spoon, gently mix ground beef, onion, eggs, breadcrumbs, garlic, milk, italian seasoning, parsley, salt, pepper, and ketchup. Do not overmix or it will create a tough loaf.
Shape this mixture into a round loaf. Place it on a large piece of tin foil. Create a loaf pan around the loaf by crimping the edges of the foil around the meatloaf. It should be about the size of the instant pot trivet.
Put the trivet into the instant pot. Make sure the handles are pointed up to make the loaf easier to remove later. Place ½ cup of water into the instant pot, then put the meatloaf onto the trivet. Lock the lid into place. Pressure cook on high power for 40 minutes. When cooking time is over, you may use the quick release.
While the pressure is releasing, you can make the glaze. In a small bowl, whisk together the ketchup, brown sugar, and worcestershire sauce.
Remove the meatloaf from the IP and place it on a baking sheet then spread the glaze on top of the meatloaf using a spatula or pastry brush. Place the glazed meatloaf in the oven broil for 5-7 minutes, or until bubbly.