def METHOD_NAME(self, config: MutableMapping[str, Any]):
    if not self.__oauth2_auth_params:
        auth = TrustpilotOauth2Authenticator(
            config, token_refresh_endpoint="https://api.trustpilot.com/v1/oauth/oauth-business-users-for-applications/refresh"
        )
        self.__oauth2_auth_params = {"authenticator": auth, "api_key": config["credentials"]["client_id"]}
    return self.__oauth2_auth_params