It’s possible. You can use frappe.publish_realtime() to show pop-up or page when the endpoint gets called.
refer:
Concerns :
@frappe.whitelist(allow_guest=True) will allow you to bypass Authorization but it’s a little bit insecure as anyone could send data to this method You cannot configure anything about headers?
what it means is, if your employee or student knows to make a post request with right parameters to the whitlisted endpoint, they can bypass bio-metric device and make a post request directly.