What was the release date of a song by  Bae Su-ji that sold more than 1.3 million copies?
Dream (Suzy and Baekhyun song): "Dream" is a song recorded by South Korean singers Suzy and Baekhyun, members of K-pop groups miss A and EXO respectively. Dream (Suzy and Baekhyun song):  It was released digitally on January 7 and later physically on January 14, 2016 by Mystic Entertainment. Dream (Suzy and Baekhyun song):  Having sold over 1.3 million copies, the song received multiple accolades at major South Korean music award shows in 2016. Bae Suzy: Bae Su-ji (; born October 10, 1994), better known by the mononym Suzy, is a South Korean singer and actress.
digitally on January 7 and later physically on January 14, 2016