Structuring event data to send to HASS in an iOS Shortcut

I wanted to make an automation that would play the contents of text messages sent to my iPhone from a specific number on a Google Nest speaker since the information in the text messages would be useful for family members.

I thought I could use an iOS Shortcuts automation with the “Fire Event” action, since I could use those for other automations. The problem is that when I tried to pass data into the event, an error would occur when attempting to run the shortcut. How do you enter data when trying to pass it into an event?