Amazon identity verification?

Good morning,

I ordered things on an Amazon account using vouchers from family (approx. 75 euros) and now I have to confirm my identity in order to continue doing this!?

I have to answer a few questions like: name, date of birth, address and date of birth

If I were to enter that, would that be it, or would a letter arrive at my home? And if so, what would be in such a letter?

I just want to use the remaining money and nothing else.

Live with my parents

LG