Examine source code of FrameSnap for YouTube

{
  "manifest_version": 3,
  "name": "YouTube Frame Screenshot",
  "version": "1.0.0",
  "description": "Adds a screenshot button to the YouTube player. Captures the current video frame as a PNG. Hotkey: S.",
  "author": "EasyPlugins",
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "yt-frame-screenshot@easyplugins",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}