Examine source code of Flash Player Emulator Plus

{
  "manifest_version": 2,
  "name": "Flash Player Emulator",
  "short_name": "Flash Player 2021",
  "description": "Play Flash content anytime, even in 2021 and beyond! This extension uses an emulator to bring back Flash games, animations, and applications directly in your browser",
  "version": "0.4.0",
  "icons": {
    "16": "icons/logo16.png",
    "32": "icons/logo32.png",
    "48": "icons/logo48.png",
    "128": "icons/logo128.png",
    "192": "icons/logo192.png",
    "512": "icons/logo512.png"
  },
  "homepage_url": "https://modernkit.one/flash-emulator/?utm_source=extension-manifest-homepage&utm_medium=extension&utm_content=extension-manifest-url",
  "permissions": [
    "<all_urls>"
  ],
  "browser_action": {},
  "background": {
    "scripts": [
      "bg.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "detection-polyfill.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": false,
      "exclude_matches": [
        "https://*.doubleclick.net/*",
        "https://*.googletagservices.com/*",
        "https://*.pubmatic.com/*",
        "https://*.adnxs.com/*",
        "https://*.outbrain.com/*"
      ]
    },
    {
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "cs.js"
      ],
      "run_at": "document_end",
      "all_frames": true,
      "match_about_blank": false,
      "exclude_matches": [
        "https://*.doubleclick.net/*",
        "https://*.googletagservices.com/*",
        "https://*.pubmatic.com/*",
        "https://*.adnxs.com/*",
        "https://*.outbrain.com/*"
      ]
    },
    {
      "matches": [
        "https://modernkit.one/*"
      ],
      "js": [
        "installed-check.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    "external/player-embed.html",
    "external/player.html"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ded2000e-1ead-4c64-abbf-398eae263609}"
    }
  }
}