Place all ingredients except black beans and garnishes in the metal insert of the instant pot. Secure the lid and turn the venting nozzle to point towards "sealing."
Push the "Soup" button and adjust the time to 20 minutes.
When timer goes off, push "Keep Warm/Cancel." Turn the venting nozzle towards "venting" to release steam. Tip: push the nozzle towards venting with a wooden spoon so you can keep your hands far away from the steam.
When all the steam has been released, unlock and remove the lid. Remove the chicken and shred with two forks. Add the chicken back to the pot with the black beans and stir.