I want to get notify whenever the new files added to a directory in FTP server. Is there any method to tell me that new files are added?
FTP does not support this natively. Hence you do one of the following:

write a short script to watch the directory  and send an email/notification (just a few lines Python)
use an existing module, aka pywatch
use an orchestration operator such as Airflow sensor, if your files are part of a larger process and you want to trigger jobs when the files arrive
How to get notify whenever a new files is added to directory in FTP server?