In a 6-qt Instant Pot, add the chicken, water, salt, and optional add-ins (if using).
Close the lid, set the vent to “sealing”, and pressure cook on high for 9 minutes. Once the 9 minutes is up, let it naturally release for 5 minutes, then manually release the remaining pressure.
(To cook from frozen, make sure the chicken isn’t stuck together and pressure cook on high for 12 minutes, then immediately release the pressure.)
Remove the lid and transfer the chicken to your cutting board to rest for 5 minutes.
You can shred it up with two forks on your cutting board or use my easy shredding method described below.
Pour the liquid in the pot into a jar (you can use this like you would chicken broth in a soup, etc…). Pour about ¼ of that liquid back into the pot (this will just help moisten the chicken a bit). Transfer the chicken back to the pot and use an electric mixer to shred it up, starting at a low speed.