[TDefaultErrorResult](API\Plugins\OnlineServicesCommon\Online\TDefaultErrorResult)< [FAuthGetExternalAuthTokenImpl](API\Plugins\OnlineServicesEOSGS\Online\FAuthGetExternalAuthTokenImpl) > GetExternalAuthTokenImpl ( const [FAuthGetExternalAuthTokenImpl::Params](API\Plugins\OnlineServicesEOSGS\Online\FAuthGetExternalAuthTokenImpl\Params) & Params )