after some searching, i found that after using:

self.player.mediaStatusChanged.connect(self.check_video_status)

and

    def check_video_status(self, status):
    # Check if the media status indicates the video has finished
    if status == QMediaPlayer.MediaStatus.EndOfMedia:
        self.video.close()  # Close the app when the video is over

the program is able to send a signal when the video over, then close the app