Rated 4 out of 5 stars

Excellent add-on...
But can any one please tell me what changes i have to make to download the file every day.
i.e. how to mentain the session alive forever?
thanks in advance

This review is for a previous version of the add-on (1.2.0). 

Usually sessions expire mechanism happen on the server side so most probably there isn't anything you can do to prevent the command from expiring. You'll need to periodically regenerate the download command.