To add a video for Henry Brinley Richards / Llandovery (Yn Iach i ti Gymru; Adieu to dear Cambria!), just enter the video‘s YouTube link:
example) https://www.youtube.com/watch?v=XXXXXXXXXXX
Search YouTube for Henry Brinley Richards / Llandovery (Yn Iach i ti Gymru; Adieu to dear Cambria!)