How to check cpp environment condition based on Old Sonarqube?

The previous worker installed sonarqube a long time ago and didn’t update it. (5.XXX)
I’ve asked the previous worker and several people, but they answered Sonarqube is not paid version.
But strangely, the C++ project was working, I can also check the C++ rules from Sonarqube.

I don’t know the answer.

I guess the previous worker used “cppcheck” for C++ with old Sonarqube version
It seems that someone is lying to me. (that is old sonarqube is paid version)

What is best and simply way to find answer?

There’s a good chance they were making use of the community-supported C/C++ plugin. GitHub - SonarOpenCommunity/sonar-cxx: SonarQube C++ Community plugin (cxx plugin): This plugin adds C++ support to SonarQube with the focus on integration of existing C++ tools.