As Provider I want to configure the ProFTPD service to show hidden files and folders.
Add the 'ListOptions "-al"' directive into the ProFTPD configuration file /usr/local/etc/proftpd_vhost_confs_pem/[ID] on a POA-managed FTP server (where [ID] is the ID of the ProFTPD service installed on a host, only one such file should exist on a server) like in the example below:
<VIRTUALHOST 188.8.131.52> ... ListOptions "-al" ... </VIRTUALHOST>
Restart the ProFTPD service for the changes to take effect:
# /etc/init.d/proftpd restart
Note: the changes can be lost after POA update, so you may need to reapply them.
Refer to the ProFTPD documentation from more information: Directory Lists and ListOptions.