Examine source code of Popup Blocker

{
  "manifest_version": 2,
  "name": "Popup Blocker",
  "version": "1.0",
  "description": "Right click to blacklist a tab from opening any new tabs",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false,
    "type": "module"
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "activeTab",
    "menus"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8a20ff39-4df1-4a36-a982-350abe9a8068}"
    }
  }
}