Add chicken breasts to Instant Pot with enough water to cover the chicken. Add salt to water. Put the lid on the Instant Pot and make sure the steam release handle in the back is set to Sealing. Select Meat cook option and let the Instant Pot do it's thing!
After the timer has gone off, you can release the pressure one of two ways. Natural release = do nothing until the metal float valve next to the steam release handle lowers. This method can take a while, possibly 30 minutes or more. The other option is Quick Release. With a towel or hand mitt, move the steam release handle to Venting. The steam will escape through this handle and the metal float valve should drop in a minute or two. After the metal float valve has dropped, you can then open the Instant Pot.
Remove chicken and shred the meat.
Clean metal insert and place back into the Instant Pot. Turn on the Saute function. Add olive oil and heat about 1 minute. Add celery and saute until just soft, about 2-3 minutes.
Add shredded chicken, cream cheese, ranch dressing and hot sauce. Mix until blended and heated through.
Serve on potato buns and top with a slice of cheddar cheese.