Examine source code of Brainly Blocker by nitro.

{
  "name": "__MSG_extensionName__",
  "short_name": "Brainly Blocker",
  "author": "nitro.",
  "description": "__MSG_extensionDescription__",
  "version": "1.0.1",
  "manifest_version": 2,
  "default_locale": "pt_BR",
  "content_scripts": [
    {
      "js": [
        "src/inject.js"
      ],
      "matches": [
        "*://brainly.com.br/*",
        "*://brainly.com/*",
        "*://brainly.in/*"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  }
}