Select the Protocol from the drop down button on the right of the Address bar.

There are three options

1. FTP No secure connection

2. FTP over SSL (Explicit)

Explicit security requires that the FTP client issue a specific command to the FTP server after establishing a connection to establish the SSL link. The default FTP server port is used. 

3. FTP over SSL (Implicit)

Implicit security is a mechanism by which security is automatically turned on as soon as the FTP client makes a connection to an FTP server. In this case, tne FTP server defines a specific port for the client (990) to be used for secure connections.