Can't find sink devices

[bgarr33434]

I'm trying to adapt https://github.com/heb-dtc/Mirroir-app for an apk I need, but the section that looks for existing miracast sink devices is not working at all. The section that I believe is the search section is posted below. Many thanks for any help here!

package com.flo.miroir;
import android.media.MediaRouter;
public interface IRemoteDisplayCallbacks {
void onRouteSelected(MediaRouter router, int type, MediaRouter.RouteInfo info);
void onRouteUnselected(MediaRouter router, int type, MediaRouter.RouteInfo info);
void onRoutePresentationDisplayChanged(MediaRouter router, MediaRouter.RouteInfo info);
}