Fatal: create repository at sftp: ... failed: unable to start the sftp session, error: EOF

Hi support,

I have added the destination successfully (IP 45.77.xxx.xxx)
https://IP_server:8090/IncrementalBackups/backupDestinations

Later, I backed up the website with the destination sftp:45.77.xxx.xxx
https://IP_server:8090/IncrementalBackups/createBackup

But it reported an error:

Will first initiate backup repo…
subprocess ssh: Permission denied, please try again.
subprocess ssh: Permission denied, please try again.
subprocess ssh: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
Fatal: create repository at sftp:45.77.xxx.xxx:/home/backup/mydomain.com failed: unable to start the sftp session, error: EOF

Repo sftp:45.77.xxx.xxx initiated for mydomain.com.
Meta data is ready…
Backing up databases…
subprocess ssh: Permission denied, please try again.
subprocess ssh: Permission denied, please try again.
subprocess ssh: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
Fatal: unable to open repo at sftp:45.77.xxx.xxx:/home/backup/mydomain.com: unable to start the sftp session, error: EOF
. [5009].

Thanks you for help me!