After creating your inMusic account and registering your new Oxygen Pro controller, you will see your product appear under your "registered products":

Simply click on the View Downloads button, to expand the window on the right hand side, which will display all included downloads and software content:

Your authorization (SERIAL) code generated automatically under the Software downloads section of this window.

For further assistance on downloading and installing the included content, please check out the support video linked in the Downloads section.