Examine source code of Tab Volume Control & Booster - VolumeSilencer

{
  "manifest_version": 3,
  "name": "Tab Volume Control & Booster - VolumeSilencer",
  "short_name": "VolSilencer",
  "version": "3.1.2",
  "description": "Control page audio below 1%, boost compatible media up to 500%, mute tabs, and quiet other tabs from a private movable widget.",
  "homepage_url": "https://labs.wiplash.ai/volume-silencer/",
  "icons": {
    "16": "assets/icons/icon16.png",
    "32": "assets/icons/icon32.png",
    "48": "assets/icons/icon48.png",
    "96": "assets/icons/icon96.png",
    "128": "assets/icons/icon128.png"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "Toggle VolumeSilencer",
    "default_icon": {
      "16": "assets/icons/icon16.png",
      "32": "assets/icons/icon32.png"
    }
  },
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+M",
        "mac": "Command+Shift+M"
      },
      "description": "Toggle the VolumeSilencer widget"
    }
  },
  "options_page": "options/options.html",
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content/content-script.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "assets/brand-mark.svg",
        "assets/ui/*.svg"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "volume-silencer@wiplash.ai",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}