Technically, Jungkook hasn't gone fully solo yet. He's still very much a member of BTS. However, he did debut his first solo single, "Seven," featuring Latto, in 2023. This single achieved a lot of success, reaching number one on several charts.
There have also been talks of him making solo appearances, with the Global Citizen Festival being one of the first. So, while he isn't fully independent, he is branching out into solo work!