There is a unique QR code on each module. You can get a serial number if you scanning it with a QR code scanning gun.
Thank you for your advice.
Can we get the unique number by using HCI/UART or other tool?
Since there are over 300K, I think that it is difficult to scan one by one.
Sorry, the serial number can only get from the QR code. We also use it in our factory. It could be fast by using a QR scanning gun.