When it comes to accessing remote directories on Linux systems, including Ubuntu, there are many different methods available to you.. If you want to make folders accessible to remote users, and do it securely, you can use sFTP..
For Linux clients, SSHFS (SSH Filesystem) is another great too to use.. It is a sub-system that comes with SSH server and enabled by default, based on FUSE for mounting remote directories over an SSH connection..
Instead of setting up an entirely new server or process for making remote directories and folders available to users, you can use your existing SSH server to do that.. No need for additional configurations or FTP servers..
This brief tutorial shows students and new users how to install and configure SSHFS on Ubuntu 18.04 | 16.04 LTS servers..