I just checked https://www.cakewalk.com/Support/Knowledge-Base/2007013384/SONAR-Platinum-Professional-Artist-Offline-Authorization but I already installed CCC, so do not see a "Help menu > Offline Activation > Export Activation Request" inside Platinum (possibly because CCC is installed and I logged into it).
 
Oh well... in the grand scheme of things is not a big deal. Things will all come out in the wash.

Edit: Installing CCC activated Platinum (forgot to include that little tid bit)

I added more information in the OP.  Its about activation when installing manually.

I downloaded the files manually. That way I could get them all downloaded simultaneously instead of the way the CCC does it., serially. This makes the downloading much faster if you have the band width and also means you can do an unattended download
The downloads went into the set CCC download folder.
Then I ran the CCC. Selecting the whole Platinum tree. During checking for updates CCC finds the installers and begins a silent installation. Again much faster because all the downloads have completed.

Running the CCC and cancelling to stop before installers run means an attended installation and I found that it did not always stop when Cancel was selected.