Are there plugins for convenient sale of keys and accounts?

Question

WordPress

How can I organize the sale of keys on WordPress? Approximately as on these links:
vkgo.deer.is
buyaccs.ru
The essence is as follows: The buyer indicates the number of accounts he wants to buy, pays, and receives a ready list in ONE file.
That is, the product will look like a text string, and in the case of buying the nth quantity, the strings will simply be added to the output file.
So - can anyone suggest ready-made plugins or solutions that have similar functionality?