Set Instant Pot to Sauté and pour in 2 t. olive oil. Add onions and cook until translucent, then add garlic and cook 2 minutes add a bit of lemon juice while stirring.
Add green chilis, chicken broth, salt, pepper, chili powder and chicken breasts. Set pot to pressure cook on high for 12 minutes. Use natural release for 10 minutes.
Remove chicken. Add cream cheese, heavy cream and artichokes to broth to melt cream cheese while shredding the chicken.
Once shredded add chicken back to pot and stir thoroughly then cook for 5 minutes on Soup setting set on LOW. Manual release and serve with cheese, avocado and sour cream.