You can use the following login details for FTP, replacing your-domain.com with your own domain:
- Server/Host: ftp.your-domain.com
- Username: your-domain.com
- Password: the password you created for FTP in the one.com control panel
- Port: 21
You can find your login details, and reset your password, in the one.com control panel under SSH & FTP on the Advanced settings tile. Click Send to request an email to create a (new) password.