Add butter to IP and turn on saute function.
Once melted, add in the onions and allow to saute for about 3 minutes.
Add in the garlic and allow to cook for about 1 minute, stirring frequently as to avoid burning.
Add in the chicken broth, cream of chicken soup, potatoes, salt, and pepper.
Place lid securely on and ensure valve is on sealing position.
Turn off saute function and switch to manual, high pressure for 10 minutes.
Once complete, do a quick release.
As pressure is releasing, combine the flour and milk together in a small bowl.
Once the steam has completely released and pin drops, remove lid and stir in the milk/flour mixture.
Turn the saute function back on and allow to heat for about 5 minutes.
Stir in the 2 cups cheddar cheese. Once melted, serve soup in bowls with desired garnishes.