I worked out a solution with sftp - so far so good. Next step is now to automize the daily backups of /home/user and the monthly system-backups with cronjobs. Therefor I am looking for an idea to solve the following challenge:
The backup-server uses 2FA authentication" ssh-publickey with otp" (google-authenticator).
Further the repos are password protected. Ok rhe passwords could be put into a variable but the otp? If you have an idea for that please let me know.