Extra links supported for operators coming from third-party packages:

airflow.serialization.serialized_objects.BUILTIN_OPERATOR_EXTRA_LINKS

airflow/providers_manager.py
"""
        Parses found provider.yaml file and adds found provider to the dictionary.
        :param path: full file path of the provider.yaml file
        :param package_name: name of the package
        """
        try:
            log.debug("Loading %s from %s", package_name, path)
            with open(path) as provider_yaml_file:
                provider_info = yaml.safe_load(provider_yaml_file)
            self._validator.validate(provider_info)
            version = provider_info['versions'][0]
            if package_name not in self._provider_dict:
                self._provider_dict[package_name] = (version, provider_info)
            else:
                log.warning(
                    "The providers for package '%s' could not be registered because providers for that "
                    "package name have already been registered",
                    package_name,
                )
        except Exception as e:  
            log.warning("Error when loading '%s': %s", path, e)
    def _discover_hooks(self) -> None:
        """Retrieves all connections defined in the providers"""
        for name, provider in self._provider_dict.items():
            provider_package = name
            hook_class_names = provider[1].get("hook-class-names")
            if hook_class_names:
                for hook_class_name in hook_class_names:
                    self._add_hook(hook_class_name, provider_package)
    def _add_hook(self, hook_class_name, provider_package) -> None: