The song, that’s free to use for YouTube videos, sounds like a jazz song and it’s in the key B-flat minor (I am a music composition specialist, and by hearing it I knew its key). It begins with a guitar loop. Last time I heard it was in 2021 or so, but I still remember how it sounded like. I think that it wasn’t from YouTube audio library either.
Might be a song from Kevin MacLeod? His songs get used a lot on the YouTubs.
https://incompetech.com/music/royalty-free/music.html
When I just searched “Kevin MacLeod jazz”, the first result was “Acid Trumpet”, which seems like it could fit your description.