code: public void startCall(final Context context, GLSurfaceView glView, boolean isAudioOnly) {
          caller = true;
          audioOnly = isAudioOnly;
  
          if (directConnectionOnly) {
              if (null == directConnection) {
                  actuallyAddDirectConnection();
              }
  
              directConnectionDidAccept(context);
          } else {
              attachVideoRenderer(glView);
  
              getTurnServerCredentials(new Respoke.TaskCompletionListener() {
                  @Override
                  public void onSuccess() {
                      Log.d(TAG, "Got TURN credentials");
                      initializePeerConnection(context);
                      addLocalStreams(context);
                      createOffer();
                  }
  
                  @Override
                  public void onError(String errorMessage) {
                      postErrorToListener(errorMessage);
                  }
              });
          }
      }
docs: Start the outgoing call process. This method is used internally by the SDK and should never be called directly from your client application
  
  @param context      An application context with which to access shared resources
  @param glView       The GLSurfaceView on which to render video if applicable
  @param isAudioOnly  Specify true if this call should be audio only