One can only guess why the find function doesn't run because you have posted an incomplete fragment of code and no error messages. If you read How do I post a question effectively? and Writeup Formatting Tips then revise your posting to provide more information, you may get more help.

In the mean time, I guess that you want the find to find files in the directory you have accessed via Net::FTP. I don't think find will do this: it will search directories on your local system.

You may be able to map/mount the remote drive to your local system, then use File::Find to search it. Or, if you are on Windows, you may be able to use UNC paths to access the directory on a remote server.