Thunderbird mobile

Hallo, I have installed the "Thunderbird " app on my smartphone as I already have this programme on my PC. Now I want to export the dat, but I get a message described above "Bestätigung der Identität" - Überschrift "Windows Sicherheit" mit Eingabe von Benutzername und Kennwort Confirmation of identity- heading windows Security by entering user name and password. I don´t know the password. Can`t I change the password? I have now entered all possible variations of passwords, but nothing fits. I have signed in to Microsoft, can still access my account, but no longer use it. This password is not accepted either. So I can`t create the QR code. Can you help me? Anne Buchholz from germany.