CURL:

root@pandora-place:~# curl -v --ftp-pasv -u sd-140494 'ftp://dedibackup-dc3.online.net/./'
Enter host password for user 'sd-140494':
* Rebuilt URL to: ftp://dedibackup-dc3.online.net/
*   Trying 62.210.18.28...
* Connected to dedibackup-dc3.online.net (62.210.18.28) port 21 (#0)
< 220 server ready - login please
> USER sd-140494
< 331 password required
> PASS
< 530 Bad credentials
* Access denied: 530
* Closing connection 0
curl: (67) Access denied: 530

FTP:

root@pandora-place:~# ftp -n -v dedibackup-dc3.online.net
Connected to dedibackup-dc3.online.net.
220 server ready - login please
ftp> user sd-140494
331 password required
Password:
530 Bad credentials
Login failed.