Some additional configuration may be required if you use private dependencies not hosted on the default registries, depending on package manager.
For maven your .m2/settings.xml needs to be configured for the specific registry you wish to use, see the settings documentation for more details.
For more information about maven registries with GitHub Actions see: https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-apache-maven-registry