MainActivity.java

import io.flutter.app.FlutterActivity;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;

import com.uxcam.UXCam; // Make sure you have this import

public class MainActivity extends FlutterActivity {
    // The methodChannel object name created in the UXCam file
    private static final String CHANNEL = "com.ur.app/uxcam"; 

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        GeneratedPluginRegistrant.registerWith(this);

         new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(new MethodCallHandler() {
          @Override
          public void onMethodCall(MethodCall call, Result result) {
            if (call.method.equals("init")) {
            String apiKey = call.argument("apiKey");
            UXCam.startWithKey(apiKey);

        }
    }
}