Verify VTU degree

I have a degree from vtu. In order to verify the degree online on VTU's website it is asking me to enter certificate ID. On my degree i can see my usn and some numbers. I tried both it keeps showing invalid. Can someone plz tell me how to verify it ?

Do i have enter it in some specific format. For example, consider my usn is 2HJ18EC789 and the numbers on my degree are A23 12345.

How do I enter it and verify ?