Remove 2-way verification from QNAP NAS using SSH
If you have forgot, deleted or the authentication-system is not working anymore (like for me), and you do not want to reset your NAS. Connect using Terminal and remove a simple file to disable the 2-way verification.
Connect to NAS using:
"Type ssh firstname.lastname@example.org where xx.xx.xx.xx is the NAS IP." (MAC)
Remove this file (Admin)
[~] # rm /mnt/HDA_ROOT/.config/.qos_config/users/admin/secondSV.conf