To add a video for Johann Sebastian Bach / Cantata No. 126, Erhalt uns, Herr, bei deinem Wort, BWV 126, just enter the video‘s YouTube link:
example) https://www.youtube.com/watch?v=XXXXXXXXXXX
Search YouTube for Johann Sebastian Bach / Cantata No. 126, Erhalt uns, Herr, bei deinem Wort, BWV 126