Hey there Samyar!
My name is Miguel Ángel and I'm an independent advisor, also a Microsoft user just like you! I'll try to help you today with your issue.
Asus VivoBook S433JQ is not equipped with a IR camera which is necessary for Windows Hello (face recognition) to work. These are not the usual normal cameras but infrared ones, so that's why the option is unavailable :(
If using Windows Hello face recognition system is truly important, you can find IR USB cameras in Amazon by searching: "IR camera usb". For example, this one: https://www.amazon.co.uk/Kaysuda-CA20-Recogniti...
I hope I've helped you today. I hope you're having a lovely 2021 so far! :)
Miguel Ángel :)
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it. All files have been analysed for malware with VirusTotal, and have shown a positive output, being completely safe to install.