IRCTC - Extension for you.

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "IRCTC - Extension for you.",
  "version": "1.1",
  "manifest_version": 2,
  "description": "This verifies the day of the travel with your preferred/often travelled Destinations and alert you if you have chosen the wrong.",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "16": "icon16.png",
      "19": "icon19.png",
      "38": "icon38.png",
      "48": "icon48.png",
      "128": "icon128.png"
    },
    "default_popup": "popup.html",
    "default_title": "Click here to enter and verify your details on IRCTC!"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.irctc.co.in/*"
      ],
      "js": [
        "contentscript.js"
      ]
    }
  ]
}