Examine source code of GB - access button

{
  "name": "GB - Access Button",
  "description": "Actual link to GB site",
  "version": "1.4",
  "manifest_version": 3,
  "action": {
    "default_icon": {
      "16": "/images/16.png",
      "32": "/images/38.png",
      "48": "/images/48.png"
    },
    "default_popup": "popup.html"
  },
  "default_locale": "en",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{32b3e3b8-bf4d-4e35-8adb-9372b894d052}",
      "strict_min_version": "42.0"
    }
  }
}