Examine source code of PMT Buddy

{
  "$schema": "https://json.schemastore.org/chrome-manifest.json",
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "realooffyy@gmail.com",
      "strict_min_version": "109.0"
    }
  },
  "name": "PMT Buddy",
  "description": "Improves your experience on some revision websites.",
  "version": "0.2.1",
  "icons": {
    "16": "./icons/icon_16.png",
    "32": "./icons/icon_32.png",
    "48": "./icons/icon_48.png",
    "128": "./icons/icon_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "service_worker": "background.js"
  },
  "action": {
    "default_title": "PMT Buddy",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "js": [
        "contentScript.js"
      ],
      "matches": [
        "*://*.physicsandmathstutor.com/*",
        "*://*.physicsandmathstutor.co.uk/*",
        "*://*.savemyexams.com/*",
        "*://*.studocu.com/*"
      ],
      "run_at": "document_start"
    }
  ]
}