CKEditor and TinyMCE add-ons require server side to be installed to upload and/or manage files and images.
The server-side of Flmngr file manager for Node.js is shipped as a microservice. Here is how you can install it:
To let N1ED know where you installed the server part of Flmngr, you need to specify the URL of the server part of Flmngr as a value of the
urlFileManagerparameter, and the URL prefix of files as
urlFiles. You can learn more about configuring the URL here.