Navigate to Tools > New Net Connection to create a new FTP connection, or just press Ctrl+N on your keyboard:

Click through these menus and you’ll be brought to the FTP client interface. Krusader will do some initial configuration since this is the first time it’s being run on your system. Once Krusader has finished installing, open it in the applications launcher or with this command in terminal: Install Krusader and its extra support package by executing this command in a terminal window: Otherwise, if you’re using GNOME or some other desktop manager, expect the install to be a bit larger since these extra packages will also be downloaded during installation. If you are using a KDE desktop environment on your system, these libraries will already be installed. Krusader relies on services provided by the KDE Frameworks base libraries. By default, it only supports the FTP protocol, but you can extend its support to SFTP and other network protocols by installing the kio-extras package. It’s a Swiss knife for managing files and comes with tools for every occasion. Krusader is another great contender for FTP clients.

Filezilla server ubuntu 18.04