Examine source code of Umanslator

{
  "manifest_version": 3,
  "name": "Umanslator",
  "version": "1.0",
  "description": "Replaces all instances of 'horse' with 'Uma Musume'.",
  "permissions": [
    "scripting"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "uma-translator@ken-dev",
      "strict_min_version": "109.0"
    }
  }
}