Begin by pressing the Sauté button on your Instant Pot and letting it heat up.
Add butter and let it melt.
Once melted, add onions, celery, and green onions. Cook for a few minutes, just to get the veggies a little tender. While this is cooking, rinse your rice until the water runs clear.
Then add salt, pepper, fresh parsley, rice, then water.
Stir everything together.
Close the lid on the Instant Pot and close the vent so it is set to sealing.
Cancel Sauté mode and press the rice button if your Instant Pot has one. If not, use the +/- buttons or the dial and set the Instant Pot to Manual or Pressure Cook mode at LOW Pressure for 12 minutes.
After the cooking cycle is finished, press the Cancel button and let the Instant Pot sit and naturally release pressure for about 5 minutes. After 5 minutes, carefully manually or Quick Release (QR) the pressure. AKA, turn the knob and let the steam release. Do not stand above the pot when doing this.
Once the pin has dropped, carefully open the lid. Fluff the rice with a fork and season with a little extra salt if needed, then serve.