Do you log onto your operating system when you boot up the computer?
If so, it should be the same password that you use there.
It doesn't want the password I thought it was. ( And I can't find anywhere on the Opera website to get in touch with them to find an answer!
PS: I have 2 or 3 accts, and it defaults to one I don't use. I click it on my primary one that I open with a PIN.