Examine source code of RoNewPorted

{
  "author": "rileyaft",
  "browser_specific_settings": {
    "gecko": {
      "id": "{A394409E-9DFE-44C2-A2A8-19C2ADBE0327}",
      "strict_min_version": "109.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.roblox.com/games/*",
        "https://web.roblox.com/games/*"
      ],
      "js": [
        "js/contentScript.js"
      ],
      "css": [
        "css/container.css"
      ]
    }
  ],
  "description": "In a single click, join the newest server of any Roblox experience, now Firefox Compatible (109.0 and above)! All credit goes to ThatTimothy for the extension creation.",
  "icons": {
    "16": "res/icon_16.png",
    "32": "res/icon_32.png",
    "64": "res/icon_64.png",
    "128": "res/icon_128.png"
  },
  "manifest_version": 3,
  "name": "RoNew",
  "version": "2.1.3",
  "web_accessible_resources": [
    {
      "resources": [
        "/html/containerTemplate.html",
        "/html/serverTemplate.html",
        "/js/injectedJoinScript.js",
        "res/notification.mp3"
      ],
      "matches": [
        "https://www.roblox.com/*",
        "https://web.roblox.com/*"
      ]
    }
  ]
}