Examine source code of CSC → Analytikill Link

{
  "manifest_version": 3,
  "name": "CSC → Analytikill Link",
  "version": "1.1",
  "description": "Adds an Analytikill icon next to the Faceit link.",
  "icons": {
    "48": "icon-48.png"
  },
  "permissions": [
    "scripting",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://csconfederation.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "analytikill.png"
      ],
      "matches": [
        "https://csconfederation.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "csc-to-analytikill@example.com",
      "strict_min_version": "91.0"
    }
  }
}