Examine source code of Desktop Everywhere+

{
  "manifest_version": 2,
  "name": "Desktop Everywhere+",
  "version": "1.0.0",
  "description": "Automatically redirects mobile website addresses to their desktop version. Lets you exclude any site you want to keep on mobile.",
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "desktop-everywhere-plus@local",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "*://*/*"
  ],
  "background": {
    "scripts": [
      "rules.js",
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ]
}