There does exists one. But when I last tried it, the experience was worse than what a native integration would give. It wasn’t streamlined as in other browsers. It doesn’t matter much since I only use YouTube Music as a PWA, which I have a relegated to another window in another browser.
Off topic, but screw you Google, for not giving a native app. Spotify meanwhile has command line third party clients even(looks at ncspot) for Premium users.
Check out this custom YouTube Music desktop client: https://github.com/th-ch/youtube-music. It has neat features like an adblocker and a download feature and many more things built-in and it’s open source. It’s available for Windows, macOS and Linux.