@leocg Yes it helps, Thank you very much!

So, I decided to use synchronization between Opera on the phone and Opera on the PC
I logged in on both devices, went to "sync" on the phone -> pairing -> scan qr -> codes match -> "What do you want to do next?" -> synchronize data
clicking on this button throws me into opera://settings/syncSetup where I am asked to enter a passphrase
I don't remember using it (although I remember my trepidation when I first saw such a thing as tabs)
"okay -- I'll just reset it"
I click on the link "reset sync settings" which takes me to https://www.sync.opera.com
I reset them
and I am told that "You have no sync data stored."
great!
but both the mobile and desktop versions continue to require a passphrase

what did I do wrong and what do I need to do to be able to use sync?