If you are the license owner, you can go to the URL below:
www.splunk.com/store/myorders
If the license was issued to someone else in your company, chances are that they can access it for you.
If that person has left, or has nothing to do with Splunk in the first place (someone in the Finance or Purchasing Dept for example), as your local Splunk admin to file a case here and request online access to the license for you.
