Examine source code of FocusFilter

{
  "manifest_version": 3,
  "name": "FocusFilter",
  "version": "1.3.6",
  "description": "Block annoying elements like YouTube Shorts and Instagram ads.",
  "homepage_url": "https://github.com/Asterohobit/focusfilter",
  "icons": {
    "16": "icons/focusfilter-16.png",
    "32": "icons/focusfilter-32.png",
    "48": "icons/focusfilter-48.png",
    "64": "icons/focusfilter-64.png",
    "128": "icons/focusfilter-128.png",
    "256": "icons/focusfilter-256.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "FocusFilter",
    "default_icon": {
      "16": "icons/focusfilter-16.png",
      "32": "icons/focusfilter-32.png",
      "48": "icons/focusfilter-48.png",
      "64": "icons/focusfilter-64.png",
      "128": "icons/focusfilter-128.png",
      "256": "icons/focusfilter-256.png"
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*",
        "*://*.instagram.com/*"
      ],
      "css": [
        "styles.css"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@focusfilter",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}