Google Calander Offset Wont Change

Im hoping someone can help me with this offset setting. I dont understand the documentation and have been trying this for 3 hours now. This is my latest attempt and offset still stays at false all the time.

Im wanting this to change so I can setup an automation 10 min before.

PLEASE

- cal_id: [email protected]
  entities:
  - device_id: mycal
    name: example
    track: true
    offset: "!!-10"

I got a notification like someone replied but I don’t see a reply. The edit button is orange now though. What does that mean?