Understanding Biometric Device integration Tool

Hi
following this article to setup auto attendance integrating with ERPnext
https://docs.erpnext.com/docs/user/manual/en/setting-up/articles/integrating-erpnext-with-biometric-attendance-devices
after downloading this tool: GitHub - frappe/biometric-attendance-sync-tool: A simple tool for syncing Biometric Attendance data with your ERPNext server
I need to know how to use it
those API key and API secret for every particular user how to make it works for all employees to get their attendance logs?