Examine source code of Instagram-Feed-Switcher

{
  "manifest_version": 3,
  "name": "Instagram Followed Feed Redirector",
  "version": "1.0.6",
  "description": "Redirects Instagram's home feed to the Following/Gefolgt variant.",
  "browser_specific_settings": {
    "gecko": {
      "id": "instagram-followed-feed@local",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.instagram.com/*",
        "https://instagram.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}