I don't think this is true.
The GPL allows you to copy & modify code for your own desires very generously.
The limitations you fear apply if you distribute the code (in source or other forms) or modifications yourself.
The GPL allows you to copy & modify code for your own desires very generously.
The limitations you fear apply if you distribute the code (in source or other forms) or modifications yourself.
However, after looking into Keycloak more closely, the software seems to be licensed with the Apache 2 license, so none of this is a concern.