Examine source code of Submit Button Disabler

{
  "manifest_version": 3,
  "name": "Submit Button Disabler",
  "version": "1.0",
  "description": "Disables submit buttons on webpages and allows re-enabling them",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "rayyarcws@gmail.com",
      "strict_min_version": "109.0"
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/16.png",
      "32": "icons/32.png",
      "48": "icons/48.png",
      "64": "icons/64.png",
      "128": "icons/128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "64": "icons/64.png",
    "128": "icons/128.png"
  }
}