8.1 and lower agents ship w/ a 10 or 14 day temporary license. After that you need to use the getlic/putlic/autolic or appserver to license the agent. do you have an account on the bladelogic licensing portal ? if not I think you should contact support. then you can use one of those utilities mentioned above to license the agent.
Alternatively you could use bsa 8.2 or higher where we do not require licensing to be run on the agents but instead do audit checks for license compliance.