Once you install, use and like DJ-MegaMenu Free you can easily upgrade to Professional edition.

With Pro version you can benefit many features unavailable in Free edition - see what's not available in Free edition

Steps to do upgrade from Free to Pro

1. Purchase the DJ-MegaMenu subscription
2. go to My Account and find your license number

Now copy the licence key and paste it in the DJ-MegaMenu module (1)

and click Go Professional (2).

Now the license key is entered and confirmed (see below screenshot [1])

and you can upgrade to Professional Edition (2)

after that you'll have Professional Edition installed:

Note: After the purchase of DJ-MegaMenu Pro subscription you can also download the Professional Edition package from download section and install it using Joomla Extensions Manager.