Download of mails from my zohoaccount with mozilla thunderbird does not work

How can I succesfully download my mails with thunderbird?
I know that it principly works, a friend of mine is doing so. But whenever I try to set up a account within thunderbird it shows a message, that username or password is wrong.
But they are right, I tried it a dozen times, also copying the name and passwort from the browser (which succesfully opens my zoho account).

Thanks in advance for help
Sylvia