How to deploy the youtube app to a toolbar with fragment in Android studio

Hi, I'm doing a recipe app because my idea is to make toolbar and in each part create fragment since I already have the screen but in a part of fragment I want to put a YouTube video, then I have searched and I see that they only do it in normal activitys but without fragment I did it in a way but I have reached the top because it says it gives an error when executing it that the fragment has not been assigned a View I do not know if what I have done is right or wrong. Please, any help on how to do it is welcome. I leave the code.

Code of my fragment:

package grupo13.recetteapp;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.youtube.player.YouTubeInitializationResult;
import com.google.android.youtube.player.YouTubePlayer;
import com.google.android.youtube.player.YouTubePlayerSupportFragment;
import com.google.android.youtube.player.YouTubePlayerView;
import grupo13.recetteapp.R;


public class tab_video_fragment extends Fragment {
    private FragmentActivity myContext;

private YouTubePlayer YPlayer;
private static final String YoutubeDeveloperKey = "xyz";
private static final int RECOVERY_DIALOG_REQUEST = 1;

@Override
public void onAttach(Activity activity) {

    if (activity instanceof FragmentActivity) {
        myContext = (FragmentActivity) activity;
    }

    super.onAttach(activity);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    inflater.inflate(R.layout.fragment_tab_video, container, false);

    YouTubePlayerSupportFragment youTubePlayerFragment = YouTubePlayerSupportFragment.newInstance();
    FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
    transaction.add(R.id.youtube_fragment, youTubePlayerFragment).commit();

    youTubePlayerFragment.initialize("DEVELOPER_KEY", new YouTubePlayer.OnInitializedListener() {

        @Override
        public void onInitializationSuccess(YouTubePlayer.Provider arg0, YouTubePlayer youTubePlayer, boolean b) {
            if (!b) {
                YPlayer = youTubePlayer;
                YPlayer.setFullscreen(true);
                YPlayer.loadVideo("2zNSgSzhBfM");
                YPlayer.play();
            }
        }

        @Override
        public void onInitializationFailure(YouTubePlayer.Provider arg0, YouTubeInitializationResult arg1) {
            // TODO Auto-generated method stub

        }
    });

    return container.findViewById(R.id.youtube_fragment);
    }
}

Code of the XML of the fragment

<!-- TODO: Update blank fragment layout -->
<FrameLayout
    android:id="@+id/youtube_fragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_centerHorizontal="true"
    android:visibility="visible" />