Add the coconut milk, peanut butter, red curry paste, chili sauce (if using) and spices to a 6 quart instant pot and mix well. Then add the chicken to the pot.
Secure the lid, close the pressure valve and cook for 5 minutes at high pressure.
Naturally release pressure (or NPR for 10 minutes, then release pressure).
Using two forks, shred the chicken right into the curry (or you can remove the chicken and cut it into chunks if you prefer)
Sprinkle with Thai basil/cilantro and crushed peanuts if desired. You can also serve this with lime wedges and add a squeeze of lime juice before eating.