Examine source code of AutoSign

{
  "manifest_version": 3,
  "name": "AutoSign",
  "author": "SleepyStew",
  "version": "0.1.6",
  "description": "Save a signature once, then draw it into browser signature fields.",
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_title": "AutoSign",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "24": "icons/icon-24.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "content/autosign.css"
      ],
      "js": [
        "src/shared/signature-engine.js",
        "content/autosign.js"
      ],
      "run_at": "document_idle",
      "all_frames": true,
      "match_about_blank": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "autosign@local.dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "strict_min_version": "142.0"
    }
  }
}