Hello Fahad Mushtaq,
Welcome to Microsoft Q&A.
I'm not sure where you saw the description that the Surface Laptop 7 supports styluses. I can clearly tell you that the Surface Laptop 7 does not support the use of styluses because there is no sensor on its screen that can recognize styluses at all.
The latest stylus at present is the Slim pen 2. You can notice in the following support link that Surface Laptop 7 is not in its support list:
Identify your Surface Pen and features - Microsoft Support
And it is clearly stated in this support link:
What to try if your Surface Pen doesn't ink - Microsoft Support
You can notice that the latest SurfaceLaptop 13-inch is not supported either.
So, if you have just purchased this device not long ago, my direct suggestion is to negotiate a refund with the seller. If someone told you before that this model of device supports styluses, then he has obviously deceived you.
Best Regards,
Ami | Microsoft Q&A Support Specialist