Use Siri
If you don’t have “Hey Siri” enabled — or you’d rather not use it at the moment — you can still call your virtual assistant with the help of your side button.
All you need to do is press and hold the Side button until Siri pops up on your screen.
You can also change your Accessibility settings so you can type your prompts to Siri after you press the side button, making it easier to use it when you’re in a place where you can’t or don’t want to be seen or heard talking to your phone. You can find this option under Settings > Accessibility > Siri > Type to Siri.