OpenGameArt.org
The Cave
Credit line
"The Cave" by Gumichan01 licensed CC-BY 4.0: https://opengameart.org/content/the-cave Author's attribution notice: Credit me as Gumichan01. It could be nice if you provide a link to my Soundcloud (https://soundcloud.com/gumichan01) or my Bandcamp (https://gumichan01.bandcamp.com/)
Where to put it: Game credits or video description. If the entry has a "Copyright/Attribution Notice", follow that.