Rinse the rice in a strainer until the water is fairly clear.
Place the rice, water, salt and butter (if using) into the Instant Pot.
Close the lid, and set the steam release valve to the “seal” position.
Either press the “Rice” button if your machine has one, of press with “Manual” or “Pressure Cook” depending on your machine, select HIGH, and use the + or – buttons to adjust the cooking time. Turn off the “Keep Warm” button, if possible, which would cause the rice to overcook.
When the time is up, all the pressure to naturally release (eg, don’t open the steam release valve). Make sure the “Keep Warm” setting is turned off. When the valve has dropped after the pressure has naturally released (this should take at least 10 minutes), open the Instant Pot, fluff the rice with a fork and serve hot.