code: def render_fetch_maven_artifacts(self):
          
          phase = 'prebuild_plugins'
          plugin = 'fetch_maven_artifacts'
          if not self.dj.dock_json_has_plugin_conf(phase, plugin):
              return
  
          koji_hub = self.spec.kojihub.value
          koji_root = self.spec.kojiroot.value
  
          if not koji_hub and not koji_root:
              logger.info('Removing %s because kojihub and kojiroot were not specified', plugin)
              self.dj.remove_plugin(phase, plugin)
              return
  
          self.dj.dock_json_set_arg(phase, plugin, 'koji_hub', koji_hub)
          self.dj.dock_json_set_arg(phase, plugin, "koji_root", koji_root)
  
          if self.spec.artifacts_allowed_domains.value:
              self.dj.dock_json_set_arg(phase, plugin, 'allowed_domains',
                                        self.spec.artifacts_allowed_domains.value)
docs: Configure fetch_maven_artifacts plugin