In a small bowl combine the lemon juice and zest, chopped herbs, garlic, crushed red pepper, and olive oil. Whisk to combine.
Place the chicken thighs in a wide flat dish so they are in a single layer. Add the herb mixture. Massage the thighs to coat with the herb mixture. Cover and refrigerate overnight. Note: If doing a quick marinade, leave the chicken out of the fridge for up to 1 hour.
Set instant pot to Saute. When the display reads HOT, remove chicken from the marinade and season with salt and sear both sides of chicken. Do this in batches if necessary to brown the chicken evenly.
Add any remaining marinade and chicken broth to the instant pot on top of the chicken. Set the Instant Pot to Manual/Pressure Cooking mode. Cook for 15 minutes on high pressure. Then let the pressure release naturally for 10 minutes, followed by manual pressure release.