Load Orto and Tap the Shortcuts icon on the bottom bar

Tap 'Shortcuts +' title button at the top of the screen

Pick the player / players you want to include in the group

Tap 'Create Group'

Tap 'Okay'

Check the Shortcut description matches what you want to happen - test it with the little play icon at the bottom right. Note that you can still add or remove speakers from the group at this stage. Then tap the 'Add to Siri' button

Amend the 'When I say' field to your choice of phrase. This is what you will tell Siri when you want to trigger the Shortcut. Tap 'Add to Siri' when ready