Examine source code of IITC Button

{
  "manifest_version": 3,
  "name": "IITC Button",
  "description": "__MSG_extDescription__",
  "version": "4.0.2",
  "icons": {
    "48": "assets/icons/48/icon.png",
    "128": "assets/icons/128/icon.png"
  },
  "default_locale": "en",
  "permissions": [
    "tabs",
    "storage",
    "unlimitedStorage",
    "webRequest",
    "alarms",
    "webRequestBlocking",
    "scripting"
  ],
  "host_permissions": [
    "https://intel.ingress.com/*",
    "http://*/*",
    "https://*/*"
  ],
  "action": {
    "default_title": "__MSG_titleDefault__",
    "default_icon": {
      "48": "assets/icons/48/icon.png",
      "96": "assets/icons/96/icon.png"
    },
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "iitc@modos189.ru",
      "strict_min_version": "109.0"
    },
    "gecko_android": {
      "strict_min_version": "113.0"
    }
  },
  "content_security_policy": {
    "extension_pages": "default-src 'self'; style-src 'self' 'unsafe-inline'; connect-src 'self' http://localhost:8000 https://*; img-src 'self' https://* data:"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "sandbox.html"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}