Combine glaze ingredients in a small bowl and set aside.
In a large bowl, combine all meatloaf ingredients (except water) with your hands.
Form mixture into a ball, flattening the top, then place meatloaf into a 7-cup glass dish. Brush top of meatloaf with 1/2 of glaze mixture.
Add water to the Instant Pot®. Insert steam rack. Place glass dish on top of the steam rack. Lock lid.
Press the Meat button and cook for the default of 35 minutes. When timer beeps, release pressure naturally for 10 minutes. Quick-release any additional pressure until float valve drops and then unlock lid.
Remove meatloaf from pot and let cool at room temperature for 10-20 minutes.
Gently tilt glass bowl over the sink and pour out any liquid. Brush on remaining glaze. Slice meatloaf and serve warm.