If you want your backup to be restored on your FTP server then you need to do the following settings:-
1) Log in to Plesk control Panel.

2) Click the "Domains" shortcut in the navigation panel.

3) Click the required domain name in the list.

4) Click on "Backup Manager".

5) Click on "Personal FTP Repository settings".

6) Enter the following settings:-
FTP server's IP address or host name.
Directory on the server, where you want to store backup files
User name and password for access to the FTP account.
Click OK once you have inserted the details.

