I would like to automatically update the status of a parent (example: DONE) when the last sub-task of the story is moved to the DONE state. it's possible?
can someone tell me the procedure to follow?
You would need an app for it. There are multiple app available: Power Scripts, ScriptRunner, Automation for JIra.
If you want to use the Power Scripts app, then you can find a tutorial here on how to accomplish what you need:
Calling all Confluence Cloud Admins! We created a new Community Group to support your unique needs as Confluence admins. This is a group where you can ask questions, access resou...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events