This tutorial is for practicing and getting to know the default Voice Control commands in iOS 13+. Similar commands exist for macOS Catalina. If you want to do this command on your iPhone, you should open this article/tutorial on your Mac or iPad.
Set up Voice Control on iOS:
Open the Settings > Accessibility > Voice Control > Enable Voice Control. Look for the Voice Control icon in the top right side of your iPhone or iPad.
Set up Voice Control in macOS:
Open System Preferences > Accessibility > Voice Control > Enable Voice Control
(Voice controls will be downloaded.) When Voice Control is enabled on your Mac, an onscreen microphone trigger will appear for sleeping and waking the microphone.
Basic iOS Navigation
Note: Voice Control will pick up other ambient voices or sometimes words spoken in a song. It’s best to use Voice Control in a quiet space. You can have non-lyrical music playing in the background.
You don’t have to hold your iOS device too close to your mouth. You may be okay with it sitting in on a table as you practice.