Examine source code of WhatsTask

{
  "manifest_version": 3,
  "name": "WhatsTask",
  "version": "1.9",
  "description": "Create tasks from WhatsApp messages",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "whatstask@ianustec.com",
      "strict_min_version": "109.0"
    }
  },
  "action": {},
  "host_permissions": [
    "https://web.whatsapp.com/",
    "https://whatstask.it/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://extensionpay.com/*"
      ],
      "js": [
        "ExtPay.js"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://web.whatsapp.com/"
      ],
      "js": [
        "ExtPay.js",
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ],
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "images/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    },
    {
      "resources": [
        "styles.css"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}