Could use help finding this Welsh hymn

I know this comes from the Welsh hymnal Canuen FFYDD,and I have a copy but it's over 1,000 pages thick.
While it comes from a Welsh hymnal that doesn't preclude its appearance in other non Welsh hymnals.

The recording is on Facebook posted by a Welsh church in 2018

https://www.facebook.com/Rhosygad/videos/2311197632243597/