im creating an extension for premiere pro with extends script I'm trying to add effects to a track using QE, but its not working, yet i m not getting any error on the execution has someone any idea

Here is my code

app.enableQE();

var qeTrack = qe.project.getActiveSequence().getVideoTrackAt(0);
if (qeTrack){
    var qeClip = qeTrack.getItemAt(0);
    if (qeClip){
        var effectToAdd = qe.project.getVideoEffectByName("Crop");
        if (effectToAdd){
            qeClip.addVideoEffect(effectToAdd);
        }
    }
}

Its just not doing anything, no error, and no result, im shure that the program is executed Thanks for help