@leocg yeah I figured out this just after I posted, but initially I didn't find any relevant post mentioning the copy/paste way to do this.

How can I recover my speed dials into my new opera that are already sync in my account ? I can see them in https://sync.opera.com/web/ and also in other speed dials, but how to bring them back into home page automatically instead of adding them manually one by one.

And the histories and passwords are already synchronized but how can I sync open tabs, and preferences ??