Start by washing and peeling the potatoes, then dice into medium sized cubes. Place a steaming basket or a trivet in the Instant Pot, and add 1 cup of water to the bottom of the pot.
Arrange the potatoes on the trivet or steaming basket (it’s ok if some fall in the water), and place the eggs on top. Secure the Instant Pot lid and adjust the valve to the sealing position.
Press on 'Pressure Cook/Manual' function, set at high pressure for 3 minutes. Allow the Instant Pot to come to pressure and cook, when it’s done, do a quick pressure release and remove the lid.
As the Instant Pot cooks the potatoes and eggs, make the dressing. In a large salad bowl, whisk together mayonnaise, mustard, sweet relish, vinegar, salt, and pepper. And you can add an optional 1/2 teaspoon of sugar if desired. Taste the dressing and adjust seasoning if desired, but keep in mind that it will be strong before the rest of the ingredients are added and flavors will be balanced then.
Transfer the eggs to an ice bath immediately preventing the eggs from becoming overcooked. And let them sit in the cold water for at least 5 minutes.
Remove the potatoes and allow to cool for a minimum of 10 minutes or longer if possible.
Add the potatoes to the dressing, and gently stir with the dressing until the potatoes are coated. Then add the diced eggs, celery, and green onion and give everything a gentle stir until well combined.
Chill the salad in the fridge for at least one hour before serving. The longer it sits in the fridge, the better the flavor is. Garnish with a sprinkle of smoked paprika before serving.