Accessing your VPS/KVM or dedicated server could be done through a number of ways such as SFTP or FTP. SFTP uses ssh which if you can access your server using ssh then you can use SFTP
The host is the IP/domain you use to access your server. Make sure to add sftp:// in front of it
The username is whatever user you want to connect to by default it is root.
Password is whatever password you use to connect using SSH.
Port is whatever your SSH port is which is usually port 22
SSH Key-based login
If you set up ssh keys
you will need to use site manager as it won't work using the standard quick connect option.
1) Select the the left most button which looks like 3 different computers and a pipe below.
Then you should see a screen like this
2) Set the protocol to SFTP instead of FTP unless you enabled FTP.
3) Set the Logon Type to Key File
4) Fill in the details
Set the Host to the server IP or domain.
Port to the ssh port which is usually 22
Set the user to the user you want to connect to which you want to connect to. Normally it would be root.
The key file is the path to the private key. Find where the .ppk or putty private key is located usually in the .ssh folder.
5) You can now edit your files