After you’ve added a shortcut to Siri on your iOS device (version 12 or later), you can run the shortcut by asking Siri the personal phrase you set on your iPhone or iPad.
Just say "Hey Siri," then say the personal phrase you created for the shortcut.
As commands and phrases are set by product, if you have more than one, you will need to set up multiple shortcuts.
Siri will tell you what product your command is linked to by the name you’ve given it or the serial number.