Examine source code of ZButton+: Undo Close Tab

{
  "short_name": "__MSG_manifest_short_name__",
  "name": "__MSG_manifest_name__",
  "description": "__MSG_manifest_description__",
  "icons": {
    "128": "icon.svg"
  },
  "version": "1.1.2resigned1",
  "author": "Vitaliylag",
  "homepage_url": "https://ZButton.ru/Undo_Close_Tab",
  "background": {
    "scripts": [
      "background/main.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon.svg?1",
    "default_title": "__MSG_manifest_BA_title__",
    "browser_style": true
  },
  "applications": {
    "gecko": {
      "id": "undoCloseTab@zbutton.ru",
      "strict_min_version": "52.0"
    }
  },
  "permissions": [
    "sessions"
  ],
  "default_locale": "en",
  "manifest_version": 2
}