Examine source code of FicLab

{
  "manifest_version": 2,
  "version": "1.0.113",
  "name": "FicLab",
  "description": "Save stories as ebook files for offline reading",
  "homepage_url": "https://www.ficlab.com/",
  "author": "Steve Gilberd <steve@erayd.net>",
  "icons": {
    "16": "icons/icon-16.png",
    "19": "icons/icon-19.png",
    "32": "icons/icon-32.png",
    "38": "icons/icon-38.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png",
    "140": "icons/icon-140.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/icon-19.png",
      "38": "icons/icon-38.png"
    },
    "default_title": "Save to eBook file"
  },
  "permissions": [
    "downloads",
    "storage",
    "<all_urls>"
  ],
  "web_accessible_resources": [
    "stream",
    "css/*",
    "fonts/*",
    "js/button.js",
    "js/integration.js",
    "html/cf-bypass.html",
    "html/modal.html",
    "icons/*",
    "img/*",
    "sites/*"
  ],
  "background": {
    "scripts": [
      "js/agent.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "js": [
        "js/bootstrap.js"
      ],
      "css": [
        "css/overlay.css"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://*.fanfiction.net/*",
        "https://*.fictionpress.com/*"
      ],
      "js": [
        "sites/fanfiction.net/ui.js"
      ],
      "css": [
        "sites/fanfiction.net/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://www.fimfiction.net/*"
      ],
      "js": [
        "sites/fimfiction.net/ui.js"
      ],
      "css": [
        "sites/fimfiction.net/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://literotica.com/*",
        "https://*.literotica.com/*"
      ],
      "js": [
        "sites/literotica.com/ui.js"
      ],
      "css": [
        "sites/literotica.com/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://archiveofourown.org/*",
        "https://www.archiveofourown.org/*"
      ],
      "js": [
        "sites/archiveofourown.org/ui.js"
      ],
      "css": [
        "sites/archiveofourown.org/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://starslibrary.net/*",
        "https://www.starslibrary.net/*"
      ],
      "js": [
        "sites/starslibrary.net/ui.js"
      ],
      "css": [
        "sites/starslibrary.net/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://www.asianfanfics.com/*"
      ],
      "js": [
        "sites/asianfanfics.com/ui.js"
      ],
      "css": [
        "sites/asianfanfics.com/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://www.inkitt.com/*"
      ],
      "js": [
        "sites/inkitt.com/ui.js"
      ],
      "css": [
        "sites/inkitt.com/ui.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://getinkspired.com/*",
        "https://www.getinkspired.com/*"
      ],
      "js": [
        "sites/getinkspired.com/ui.js"
      ],
      "css": [
        "sites/getinkspired.com/ui.css"
      ],
      "run_at": "document_end"
    }
  ],
  "applications": {
    "gecko": {
      "id": "ficlab-helper@mozilla.org",
      "strict_min_version": "78.0"
    }
  }
}