How to assign number = role_id value?

Question

Python

Hello , there is a store , and it is possible to buy goods from the store , but the purchase is carried out by the method
!!buy 12345567890123 | and it is very difficult for other people to enter the role id, The store has a counter (item number)
How to make it so that you can buy a product using the !!buy number method

Store - https://pastebin.com/9sRc8UNF
Buying a role - https:/ /pastebin.com/1Eusgcm6