Add butter to the inner pot and turn the sear/sauté on high. While the butter melts, cut your onion into thin slices. I cut the slices in half, so they are about 2" in length.
Add the onions and the salt to the inner pot with the melted butter and continue to sauté until they just start to brown. This takes about 5 minutes.
When the onions just start to brown, put the Tendercrisp lid down and AirCrisp on 390° F for 5 minutes. The onions should be nice and brown and caramelized.
Chop up the green onions, both the green and the white part.
Add the sour cream, onion powder. Stir to combine. Add the green onions & cream cheese. Stir to combine and break up cream cheese.
Put the pressure lid on and turn the valve to vent. Select the slow cook function on high. The default setting is 4 hours, but you only need to cook for 1 hour. This will melt the cream cheese and allow all the flavors to combine and develop in the dip.
You can serve this dip warm or put it in the fridge to chill.
You can speed up making this dip, by using sear/saute on medium-low to melt the cream cheese and combine the ingredients together. I found that slow cooking the dip did develop a better flavor, but it is not necessary.