Pour water and lemon juice into the Ninja Foodi or Instant Pot.
Add lemon slices and dill.
Add the wire rack/trivet into the pot at the lowest setting.
Add the fillets to the rack/trivet, cut to fit if needed.
Add the lemon slices on top of the salmon.
Sprinkle with salt and pepper.
Secure the pressure cooker lid that comes with the Ninja Foodi.
Make sure the valve is set to 'seal', use the manual settings and cook on high pressure for 4 minutes. Add an additional minute if the fillet is frozen.
Once done, release the valve to vent (quick release) and then open the lid.