Rinse rice under running water. Keep rinsing and draining the water until water turns clear, this happens after rinsing 7 to 8 times.
Then transfer the rinsed rice to a strainer. Let it sit there for few minutes until there's no water dripping from the strainer. Rice should not feel wet at this point.
Then add the rice to the Instant Pot along with 1 cup of water. Close the lid and press the manual or pressure cook button. Cook on high pressure for 5 minutes with pressure valve in the sealing position. Let the pressure release naturally.
While the rice is cooking, add vinegar, salt and sugar to a pan and place it on low-medium heat. Stir until sugar dissolves and everything is well combined, there's no need to boil the mixture. Remove pan from heat and let it cool.
Once the pressure has naturally released, open the lid and then transfer the rice to a glass bowl. Add the vinegar-sugar-salt mixture to the rice.
Mix slowly using a wooden spatula until everything is well combined. Then let the rice cool down to room temperature before using in sushi rolls. You can even transfer it to a refrigerator for 15 to 20 minutes to speed up the cooling process if you want.
Notes
The amount of vinegar can be adjusted to taste. If you prefer a stronger flavor of vinegar in your sushi rice, then you can additional 1-2 tablespoons of it here.