This melody can be found in episode 6 of the drama called "My Dearest (2023)". This is a Manchu Lullaby called Bebu Mudan.

- Lyrics -
baby, baby, my baby
baby baby my pretty baby
my treasure go to sleep
grow well, my small baby
gentle small wind
even birds fly to their nests
go to sleep, my pretty baby

Disclaimer: I do not own the rights to the music used in this video. This video is for entertainment purposes only.