If you are updating from previous versions of F9, Support will be able to assist you in getting a serial number.
The product can be installed without the serial number, but it will be needed within 30 days of installation.
The serial number contains the number of authorized users for F9.
There will be an approximate 1 week turnaround if your client record shows you have already have maintenance on F9.

If you are installing the product for the first time, the request should go through your Account Executive.