Examine source code of Mute Tab

{
  "manifest_version": 3,
  "version": "0.3.1",
  "name": "Mute Tab",
  "description": "__MSG_description__",
  "default_locale": "en",
  "permissions": [
    "storage",
    "contextMenus"
  ],
  "optional_permissions": [
    "tabs",
    "favicon"
  ],
  "optional_host_permissions": [
    "*://*/*"
  ],
  "background": {
    "service_worker": "worker.js",
    "scripts": [
      "worker.js"
    ]
  },
  "homepage_url": "https://webextension.org/listing/mute-tab.html",
  "icons": {
    "16": "data/icons/16.png",
    "32": "data/icons/32.png",
    "48": "data/icons/48.png",
    "64": "data/icons/64.png",
    "128": "data/icons/128.png",
    "256": "data/icons/256.png",
    "512": "data/icons/512.png"
  },
  "action": {
    "default_popup": "",
    "default_title": "Tab can play audio.\n\nUse options page to switch to simple mode."
  },
  "commands": {
    "_execute_action": {},
    "focus-mode": {
      "description": "Focus Mode"
    },
    "toggle-tab": {
      "description": "Toggle Mute"
    },
    "toggle-other-tabs-window": {
      "description": "Toggle Mute for Other Tabs in This Window"
    },
    "toggle-tabs-other-windows": {
      "description": "Toggle Mute for Tabs in Other Windows"
    },
    "toggle-all-other-tabs": {
      "description": "Toggle Mute for All Other Tabs"
    },
    "mute-tab": {
      "description": "Mute Tab"
    },
    "mute-other-tabs-window": {
      "description": "Mute Other Noisy Tabs in This Window"
    },
    "mute-tabs-other-windows": {
      "description": "Mute Tabs in Other Windows"
    },
    "mute-all-other-tabs": {
      "description": "Mute All Other Tabs"
    },
    "unmute-tab": {
      "description": "Stop Muting Tab"
    },
    "unmute-other-tabs-window": {
      "description": "Stop Muting Other Tabs in This Window"
    },
    "unmute-tabs-other-windows": {
      "description": "Stop Muting Tabs in Other Windows"
    },
    "unmute-all-other-tabs": {
      "description": "Stop Muting All Other Tabs"
    },
    "close-other-noisy-tabs-window": {
      "description": "Close Other Noisy Tabs in This Window"
    },
    "close-noisy-tabs-other-windows": {
      "description": "Close Noisy Tabs in Other Windows"
    },
    "close-all-other-noisy-tabs": {
      "description": "Close All Other Noisy Tabs"
    }
  },
  "options_ui": {
    "page": "data/options/index.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b0ee5055-362a-44d4-804f-7358ef544ec9}",
      "strict_min_version": "128.0"
    }
  }
}