Examine source code of Invidious

{
  "manifest_version": 2,
  "name": "Invidious",
  "version": "2.0.0",
  "description": "Redirects you to invidio.us most healthy site whenever you visits or get redirected by any site to Youtube.com",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://invidio.us/",
        "https://invidio.us/*"
      ],
      "js": [
        "invidious.js"
      ]
    }
  ],
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*.youtube.com/*",
    "*://*.youtu.be/*"
  ]
}