Examine source code of YouTube Frame Copier

{
  "manifest_version": 3,
  "name": "YouTube Frame Copier",
  "version": "1.0",
  "description": "Copy the current YouTube video frame to clipboard with a shortcut.",
  "permissions": [
    "scripting",
    "clipboardWrite",
    "activeTab"
  ],
  "host_permissions": [
    "https://www.youtube.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "copy-frame": {
      "suggested_key": {
        "default": "Ctrl+Shift+Y"
      },
      "description": "Copy current YouTube video frame to clipboard"
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ffdd5e30-9cfc-4be3-900f-37f605cf1625}"
    }
  }
}