pjsip enable loudspeaker on ios des not work

I use this code to try to enable loudspeaker on iOS device. ``` pjmedia_aud_dev_route route = PJMEDIA_AUD_DEV_ROUTE_LOUDSPEAKER; pj_status_t status = pjsua_snd_set_setting(PJMEDIA_AUD_DEV_CAP_INPUT_ROUTE, &route, PJ_FALSE); if (status != PJ_SUCCESS){ NSLog(@"Error enabling loudspeaker"); } ``` I know I can use `kAudioSessionProperty_OverrideAudioRoute` but I want to enable it by pjsip because then I can pass `PJMEDIA_AUD_DEV_ROUTE_BLUETOOTH` to route and enable bluetooth. I use pjsip 1.8.5 on iOS 5.0