Charlix XCX originally created the song for one of her albums. Back then, it was titled "Glow" and the lyrics were about a potential romantic interest. She explained, "The song was originally about falling in love with someone in the club 'cos they had that 'glow' about them."
When Charli met BTS, they talked about collaborating, so she sent "Glow" to BTS. The guys liked the song, but wanted to change the lyrics to reflect the sort of message they wanted to share with the BTS Army. Charlie said, "I don't usually write songs like that so it was cool for me to be involved with this new kind of emotion."