All ServePHP servers require SSH key authentication & unable to be accessed without passwords. Therefore you will need to use SSH authentication to connect to your ServePHP database using a GUI client.

Make sure that you select your private SSH key when selecting the SSH key to use for authentication. 

For example, when using the Sequel Pro database client:

To access files you can connect the FTP client to the server.

For connect FTP to server you can use any FTP software like FileZilla.

You make connection like given

For making connection first you have to select the protocol as SFTP.

Then add your server IP address as Host.

After that select Logon Type i.e. File Key & add User

At last add Key File i.e. your path to private SSH key file.

Now click on the Connect button to connect using FTP.