What is the ordering script?

Question

SVG

Good afternoon
On many sites I see a standard window for placing an order - the address entry system is very well thought out - thanks to integration with KLADR, the buyer enters the address without errors. Here is an example - https://blossomsib.com/basket?
Please tell me what kind of script / service is this

Answer 1

Because fill only works on elements inserted inline.

Answer 2

https://dadata.ru/ service to help you enter anything.

Answer 3

With the help of data, this can be done, but I would like to know the name of this ready-made solution