Use the same Google account whose music you want here.

Press F12 (or Ctrl+Shift+I), then click the Network tab.

Press F12, then click the Network tab.

1. In the Network filter box, type: browse
2. Refresh the page (F5) or click Library in YouTube Music
3. Click a row that is POST to music.youtube.com (status 200)
4. Right‑click that row → Copy → Copy as Node.js fetch (Not “Copy as fetch” — that one drops the Cookie.)
5. Right‑click → Copy → Copy as Fetch (or copy Request Headers)

Paste the whole copied text (or only the Cookie line). We detect what you pasted automatically.