If you want to know how to screenshot Instagram story on iPhone X or a newer model, then press and hold the volume up and power buttons. After that, you will see a flash and hear a shutter sound. Now, a screenshot will be saved on your iOS device. You can view the screenshot by opening the photos app on your smartphone. If you are using an iPhone 8, then press the Power and Home button simultaneously to take a screenshot. Release the buttons when you hear the shutter sound.