Figured it out, by reaching out to our support folks.
All you need are the following.
- Valid controller serial number to open case.
- ASUP from WFA (manual generation) and the WFA System ID
I am sure you know how to get #1, and #2 as explained by sinhaa.
Thanks to Alex from Support on this info.
BTW stefan, do let me know the support case number once opened I will close my internal loop on the same.