First, pour 1/2 cup of water or chicken broth onto the bottom of your Instant Pot and then place the trivet on top of the water.
Then, optionally season your chicken breast with salt and pepper, to taste. You can also use any other kind of seasoning you want.
Place chicken breast on top of the trivet and close Instant Pot.
If you are using thawed chicken breast, cook on high pressure for 8-10 minutes. If you are using frozen chicken breast, cook on high pressure for 18-20 minutes. Medium chicken breasts will be cooked after 18 minutes, but another larger will need a longer cook time. It will take around 10 minutes to build up enough pressure before your Instant Pot starts to count down.
When the timer goes off, quick release the Instant Pot. Use a meat thermometer to make sure the thickest part of your chicken breast is at least 165ºF. If it's not, continue cooking chicken breast in increments of 2 minutes.
Once fully cooked, you can prepare it any way you wish. Feel free to dice or shred it.