A valid iLO user account and password is required for each XML script when using LOCFG.PL. The user account must have appropriate lights-out privileges to process the request.
The locfg.pl script connects to the iLO management processor using a Secure Sockets Layer (SSL) connection.
So to answer you question you need an valid SSL cert and key.
It can be cert which is set from factory or you may use CA siged certs which included private key
Refer to the installation instructions in the following HPE Lights-Out XML PERL Scripting Sample
https://support.hpe.com/hpsc/swd/public/detail?swItemId=MTX_76bfa460792d4f7cbc0aac234e#tab3
Refer to the following documents for more details