I am pretty sure my account and password was OK.
1) i tried my old avast account, xxx@icloud.com, the same error.
2) then i tried login with google account, with is qq41411@gmail.com, still can't login.
3) finally i register a new avast account with qq41411@gmail.com, the same error again which the screenshots above.
i have used avast password software for like a year or more, both MAC and iPhone, but recently i found mac account sync failed, so i uninstall it and reinstall try to fix it. I don't know why and what should i do, it was terrible my iPhone account can't sync between mac and iPhone.