In a small bowl or measuring cup, whisk together the broth or water, coconut aminos (or soy sauce), rice vinegar, fish sauce, maple syrup, sriracha (if using), sesame oil, and minced garlic until well combined.
Place the raw chicken thighs in a zip-top bag or airtight container and pour in the marinade. Seal and marinate in the refrigerator for at least 15 minutes, or up to 1–24 hours for more flavor.
Transfer the marinated chicken and all of the marinade to the Instant Pot. It is fine if the thighs overlap and are not in a single layer.
Close the lid and set the pressure release valve to sealing. Pressure cook on High for 8 minutes (use 10 minutes for bone-in thighs or 14 minutes for frozen thighs). Allow the pot 5–10 minutes to come to pressure before the cook time begins.
When the cook time finishes, perform a quick release to release all pressure. Open the lid and check the largest thigh with a meat thermometer; the internal temperature should read at least 165°F (74°C).
Use tongs to remove the chicken to a plate, leaving the cooking juices in the pot.
Press Sauté on the Instant Pot. If using, whisk the tapioca flour or cornstarch into a small amount of cold water to make a slurry, then stir it into the hot juices. Bring to a boil and cook 3–5 minutes, stirring occasionally, until the sauce thickens.
Either return the chicken to the pot to coat with the sauce or spoon the sauce over the chicken before serving.