From the lemongrass remove the outer skin and chop finely
Use a food processor or a hand stick blender to process the lemongrass plus chopped or diced, onion, garlic, ginger, and chili.
Also, chop finely one kafir lime leaf if you have it (remove the middle vein and dice finely the rest of the two sides of the leaf.
Add in the oil and blitz into a paste. If it is not wet enough add 1or 2 tablespoons of water to wet up the paste so that it just a little bit runny.
Then add all the rest of the ingredients (except chicken stock) to the blitz paste and stir to mix well.
Now add the chicken stock (with about 1 tablespoon of the blitzed paste) and mix to the instant pot bowl, followed by the chicken and the last remaining kafir lime leaves.
In order to stop the instant pot from giving a burning warning keep the peanut sauce blitz off the bottom of the instant pot
Then using a spoon put half of the peanut sauce on top of the chicken
Cook for 20 mins on low pressure and 10 mins natural release
After cooking scrape the peanut sauce off the top of the chicken and mix into the chicken stock that remains in the instant pot bowl. Then take out the chicken.
Also, add the rest of the peanut sauce mix into the instant pot bowl.
If it is too runny - take out the chicken and turn on the instant pot to sauté and reduce the sauce till it is slightly thicker.
This is more a personal choice as to how thick you want the chicken sauce.