Examine source code of SoundSphere

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "SoundSphere",
  "version": "1.1",
  "description": "Smart volume boost and 10-band EQ for your browser audio. Boost, shape, and tame loudness without leaving the tab.",
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon/speaker16px.png",
      "32": "icon/speaker32px.png",
      "48": "icon/speaker48px.png",
      "96": "icon/speaker96px.png",
      "128": "icon/speaker128px.png"
    }
  },
  "icons": {
    "16": "icon/speaker16px.png",
    "32": "icon/speaker32px.png",
    "48": "icon/speaker48px.png",
    "96": "icon/speaker96px.png",
    "128": "icon/speaker128px.png"
  },
  "options_page": "options.html",
  "background": {
    "service_worker": "background.js",
    "type": "module"
  },
  "permissions": [
    "storage",
    "tabs",
    "tabCapture"
  ],
  "host_permissions": [
    "*://*.youtube.com/*",
    "*://music.youtube.com/*",
    "*://*.bandcamp.com/*",
    "*://*.soundcloud.com/*",
    "*://open.spotify.com/*",
    "*://music.amazon.com/*",
    "*://*.twitch.tv/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*",
        "*://music.youtube.com/*",
        "*://*.bandcamp.com/*",
        "*://*.soundcloud.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "fonts/JetBrainsMono-ExtraBold.woff2"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}