Examine source code of 360PanoramaViewer

{
  "manifest_version": 3,
  "name": "360PanoramaViewer",
  "version": "1.0",
  "description": "View images as 360-degree panoramas",
  "permissions": [
    "contextMenus"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "icons": {
    "48": "icon.svg"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "viewer.html",
        "viewer.js",
        "lib/three.module.min.js",
        "lib/three.core.min.js"
      ],
      "matches": []
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "360panoramaviewer@gumpf.app",
      "strict_min_version": "60.0"
    }
  }
}