manifest.json

{
    "name": "Show GeForce Now on Steam",
    "description": "Shows if you can play games in GeForce Now while you are in steam website",
    "version": "1.8",
    "manifest_version": 3,
    "permissions": [],
    "content_scripts": [
        {
            "matches": ["https://store.steampowered.com/*"],
            "css": ["extstyles.css"],
            "js": ["data.js", "contentScript.js"]
        }
    ],
    "action": {
        "default_title": "Show GeForce Now on Steam",
        "default_icon": {
            "16": "/images/icon16.png",
            "32": "/images/icon32.png",
            "48": "/images/icon48.png",
            "128": "/images/icon128.png"
        }
    },
    "icons": {
        "16": "/images/icon16.png",
        "32": "/images/icon32.png",
        "48": "/images/icon48.png",
        "128": "/images/icon128.png"
    }
}