Examine source code of JobScrub

{
  "manifest_version": 3,
  "name": "JobScrub for Indeed",
  "version": "1.1.1",
  "description": "Reveals posting dates and blocks toxic employers on Indeed.",
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "host_permissions": [
    "*://*.indeed.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "jobscrub@pocketdiallabs.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "ExtPay.js",
      "background.js"
    ]
  },
  "web_accessible_resources": [
    {
      "resources": [
        "block.png",
        "update.html"
      ],
      "matches": [
        "*://*.indeed.com/*"
      ]
    }
  ],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.indeed.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "*://*.indeed.com/*"
      ],
      "js": [
        "injected.js"
      ],
      "world": "MAIN",
      "run_at": "document_start"
    }
  ]
}