To-Do trigger when I mark a task as done

[Warnolf]

I would like a trigger when I mark a To-Do task as complete. 
I use To-Do, but my extended project team uses Trello. I have a Flow that creates a To-Do (Outlook task) when a Trello card is created. I would like to use Flow to keep the Trello card and tge To-Do task in sync.