manifest.json

{
    "manifest_version": 3,
    "name": "RoAdditions",
    "version": "0.1",
    "description": "Adds new features to Roblox",
    "icons": {
        "48": "icon.png"
    },
    "action": {
        "default_title": "RoAdditions",
        "default_popup": "popup.html"
    },
    "permissions": ["storage"],
    "host_permissions": ["*://*/*", "https://userstyles.world/*"],
    "content_scripts": [
        {
            "matches": [
                "*://www.roblox.com/*",
                "*://web.roblox.com/*",
                "*://roblox.com/*"
            ],
            "js": ["loader.js"],
            "run_at": "document_end"
        }
    ],
    "web_accessible_resources": [
        {
            "resources": ["index.js", "playbtn.js"],
            "matches": ["<all_urls>"]
        }
    ],

    "options_ui": {
        "page": "popup.html",
        "open_in_tab": true
    }
}