"Extra keys not allowed @ data['title:']"?

Why doesn’t this work? I’m trying to send notifications using the iOS component. The action in the automation looks like this:

action:
  service: notify.notify
  data: 
    title:: 'Title'
    message: 'Message'

I get this error:

ERROR (MainThread) [homeassistant.core] Invalid service data for notify.notify: extra keys not allowed @ data['title:']. Got 'Title'

I don’t understand what the extra keys are?

You put two colon after title instead of one

Argh! :weary:

Thanks @namadori!