How to sart working with fedex.com with account number ?

I registered myself at fedex.com and I recieved email I registered with with messages :

Thanks myname, for creating a FedEx user ID and for taking the time to sign up. With a user ID, you can easily track shipments, create an address book, manage your account and more. Your account details : ...

and button to login on the site.

But from "Account Management" tt was proposed to enter a nine-digit FedEx account number :

https://img001.prntscr.com/file/img001/m00xyXYcRZyNDYcalMLXhw.png

Where can I get this account number ? I tried to search under my profile and did not find anything ...

I need to start working at Developers portal to create test key...