Examine source code of BBOalert

{
  "manifest_version": 3,
  "name": "BBOalert",
  "description": "Auto alert on BBO",
  "version": "9.1.2.2",
  "icons": {
    "16": "BBOalert16.png",
    "48": "BBOalert48.png",
    "128": "BBOalert128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "iframe/globals.js",
        "iframe/BBO_DOM.js",
        "iframe/blogspot.js",
        "iframe/functions.js",
        "iframe/BBOalertData.js",
        "iframe/BBOalert.js",
        "iframe/BBOalertFind.js",
        "iframe/BBOalertConfig.js",
        "iframe/custom_syntax.js",
        "iframe/BBOalertUI.js",
        "iframe/BBOalertOptions.js",
        "iframe/BBOobserver.js",
        "iframe/BBOobserverHandlers.js",
        "iframe/webStorage.js",
        "iframe/BBOalertPlugin.js",
        "iframe/init.js"
      ],
      "matches": [
        "https://*/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1c6494f5-d8e3-4877-a269-2adf40fc1f9a}"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://docs.google.com/*",
        "https://drive.google.com/file/d/*/preview",
        "https://drive.google.com/file/d/*/view",
        "https://github.com/*",
        "https://raw.githubusercontent.com/*",
        "https://www.dropbox.com/*",
        "https://dl.dropbox.com/*",
        "https://dl.dropboxusercontent.com/*",
        "*://www.bridgebase.com/v3/*",
        "*://tinyurl.com/*"
      ],
      "css": [
        "BBOalert.css"
      ],
      "js": [
        "jquery-3.5.1.min.js",
        "googleDocs.js",
        "BBOalertIframe.js",
        "main.js"
      ],
      "all_frames": true
    }
  ]
}