Install Flmngr file manager server side
In order to let your Flmngr file manager dialog to list files, upload and modify them on the server, you need to install official server side script to add such support to your server.
Users who use CMS integrations like Drupal already have backend installed and configured. Users of custom integrations (when you install JS snippet or CKEditor or TinyMCE plugin) need to integrate the file manager backend to their CMS or framework manually.
This is not too complicated and we have implementations for different environments, please choose below.