Marinate your tilapia fillets with lemon juice, salt and pepper and let them rest in the fridge overnight or for at least one hour.
Place the fish with its marinade into the Instant Pot and close the lid.
Cook at high pressure for 4 minutes.
When cooking time is complete, wait for a natural pressure release (or for at least 10 minutes).
Open the lid, top with parmesan and serve :)
Video
Notes
Feel free to add more lemon juice if needed.
If you are cooking more than 4 fillets at the same time in your Instant Pot, you may have to increase the cooking time by a minute or two, especially if you are using frozen fillets.