How to automatically notify user (not assignee) when tasks status changes

How to automatically notify user (not assignee) when tasks status changes

Hi,

One of my team is using extensively Books tasks to follow business workflows. We are missing notiification to the creator of the ask, that a task has been completed.
I'm trying to find Books automation and workflow, but Tasks are not available.
I also tried to get trigger through Zoho flow, but tasks are not in the list of triggers.

What would be the best way to notify automatically a user (other than the assignee) of the status change of a books' task ?

Thanks