Pour chicken broth in the bottom of the Instant Pot.
Place the chicken breasts in the pot, then top with butter, green pepper slices, onion slices, garlic, Italian dressing mix, paprika, and salt and pepper.
Place lid on top of Instant Pot and turn valve to SEALING. Press MANUAL button (or PRESSURE COOK button) and set timer to 15 minutes (22 minutes if chicken is frozen).
When chicken is finished cooking, move valve to VENTING and do a quick release of the pressure.
Remove chicken and transfer to a plate or cutting board (leaving liquid in the pot). Shred or slice the chicken.
Return shredded chicken into liquid in the Instant Pot.
Spoon shredded chicken (I used a slotted spoon so that it doesn't make the buns soggy) onto buns and top with pieces of cheese.
Notes
Another yummy option is to toast your bread in a 375℉ oven for 4-5 minutes, then top with meat and cheese and stick back in the oven for 5 minutes to melt the cheese and make it nice and gooey.