Attendants dashboard using barcode

I am thinking for designing approximately like this system like that at the following link https://scrum-system.com/smart-assembly-point.html

I will provide the card with barcode or the barcode itself

Design criteria
Barcode reader either a in contact with the dashboard directly like in supermarket or any suggestion will be welcomed
Barcode reader that communicate with dashboard after I scan the barcode.
I will provide the Pc screen by itself
Dashboard must show the names and number of missing people who did not scanned yet their barcode
Dashboard must show the names and number of presented people who did scanned their barcode

Thanks