I bought her from a breeding center for €300 Euro on 2024.04.30.

I have the breeding center's certificate and the assignment (transfer of ownership) document.

My bird has a microchip, and the microchip number is also visible at least on one of the documents. My previous bird had a ring on one of her legs, and a ring number.

Depending on where you buy a bird from, they (the breeder or the breeding center) will give you a bird either with a ring or with a microchip, and they always give at least one paper to you.