It looks like "purse" is from "WebMoney Purse", another russian site. That field "purse" doesn't change when you choose other withdraw methods though, so it could just be a bad Russian translation of "account number".

Example, this quote, which makes no sense unless you realize this is a non-native speaker using approximate translations. "Purse" could either be "virtual currency wallet" or "banking account number" or both or anything...