Re: Where i can get a initial Key Code for my codec?
You went to the right place, if you are entitled to the upgrade you will be asked to enter your serial number and the system will return the key.
If you are not getting a key and being informed you are not entitled and believe you are you should contact Poly service in your region for assistance.
Looking at the dashboard image you attached it would appear as if that serial number had not renewed services which provides entitlement since it was purchased back in mid-2015.
You can also purchase a license to get the current software please reach out to your Poly reseller for a quote of that (5150-58712-001, RealPresence Group Series software upgrade version 6.2.x and all previous version applicable to all Polycom RealPresence Group Series models, including the RealPresence Group Centro)