Control the YouTube Music tab in the browser with your keyboard.
The Play Music command searches YouTube Music songs, albums, artists, and playlists, or YouTube videos, and starts the chosen item in the selected browser. The source dropdown, the Search in… action (⌘K), and the Play Music Source preference choose which catalogue it reads; albums, artists, and playlists open as grid tiles, and album and playlist tiles start the whole queue rather than a single track, with ⌘↵ opening the track list instead. With the search bar empty it shows your library instead — Albums, Artists, Playlists, Liked songs, and Recently played, each opening into its own list — read from the signed-in music tab, so that tab needs to be signed in to YouTube Music. Now Playing shows the current track, the recently played tracks and the queue, with transport and rating actions. How many recently played tracks to list is set in the extension preferences. Both follow the playback setup below; no additional permissions are required.
Play Music accepts a launch context that makes Add to Queue the primary action, so a hotkey or deeplink can queue a track without opening the action panel:
raycast://extensions/danieldbird/youtube-music/play-song?launchContext=%7B%22mode%22%3A%22add%22%7D
The same context takes a source, which saves opening the dropdown when you only ever search one catalogue. Assign a hotkey to a Quicklink pointing at one of these and each scope gets its own keystroke:
raycast://extensions/danieldbird/youtube-music/play-song?launchContext=%7B%22source%22%3A%22albums%22%7D
source accepts both, ytmusic, albums, artists, playlists, or youtube.
The extension controls your browser via AppleScript by running JavaScript in the YouTube Music tab. You must enable Allow JavaScript from Apple Events in the browser you select in the extension preferences; otherwise commands will fail (often with "Unknown Error").


After enabling this setting, pick the same browser (or WebCatalog app) in the extension’s Browser where YouTube Music opened preference.
Credit to @alexstrnik for the Yandex Music extension which this extension was based on.