Examine source code of StackBack

{
  "manifest_version": 3,
  "version": "1.6",
  "name": "StackBack",
  "description": "Adds random backgrounds to stackoverflow and stackexchange",
  "host_permissions": [
    "https://api.unsplash.com/*"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "icons": {
    "16": "/icons/StackBack_16.png",
    "32": "/icons/StackBack_32.png",
    "48": "/icons/StackBack_48.png",
    "128": "/icons/StackBack_128.png"
  },
  "options_page": "options.html",
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://stackoverflow.com/*",
        "https://*.stackexchange.com/*"
      ],
      "js": [
        "js/stackoverflow.js"
      ],
      "css": [
        "css/stackoverflow.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "info@vincentvansetten.com",
      "strict_min_version": "101.0"
    }
  }
}