HELP: How to get gift card ID for SBI credit card Amazon gift card

Recently I got the Amazon gift card from the SBI for the simply clickz credit card. But when I’m trying to add the voucher, it is giving the error “Sorry. We are unable to add this Gift Card to your account. Please try again after sometime.”

I have tried to add it to other accounts too, but same error is showing.

I have contacted Amazon care, but they are asking for the gift card ID no.  But the bank only gave me the code of the voucher.

So, how can I find the gift card ID no.?

Also if anyone faced the same problem before, then tell me how can I solve it..