I use either chicken OXO cubes or my chicken broth recipe for flavouring my chicken stock in the Instant Pot. You could use either of these or go with your own favourite. To make stock with a chicken OXO cube crumble the stock cube into a jug of 250ml of boiling water and then mix well with a fork.
It will then look like a really thin gravy. I did get a very small amount of chicken breast stuck to the bottom of the steamer shelf, but such a tiny amount and it came off in my hand and was still great for eating! I have had people say that they get this a lot more than me and its down to them cooking it for 20 minutes rather than 18.
We have found the best place to source chicken breasts to make Instant Pot Shredded Chicken is from ButcherBox. You even receive free bacon and $10 off your first order when you sign up with this link.For the best chicken stock in your recipes I would recommend Kettle & Fire. Unfortunately they are not available in the UK so if you are UK based I would use OXO cubes.