accessing the management interface

Hello I tried accessing the management interface by entering 192.168.1.1 in my browser, but the system prompted me to enter a serial number. I entered the serial number on the device, but it kept saying it was incorrect. Yes, I tried using the default username and password, but the system still asked for the serial number. I used a paperclip to hold the reset button on the device for about 10 seconds until it restarted. Then, I tried logging in with the default username and password. The issue still persists after the reset. Please help me resolve this problem.