Examine source code of Caption Customizerv2

{
  "manifest_version": 2,
  "name": "Caption Customizer",
  "version": "1.0",
  "description": "Customize video captions on popular video platforms.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3d790161-89b7-4511-b2ec-4fc5d75c9ded}"
    }
  }
}