# Payment System Purchasing USDT and TANPIN tokens directly on the website. We've developed a system for buying USDT and TANPIN tokens directly on the site using a regular bank card. Currently, only RUB is available, but the geographical availability may expand later. ### Purchase Rate It is dynamically calculated based on the formula `C + C * (B / 100)` `C` - is the exchange rate `B` - is the markup to the rate. Upon payment confirmation, the user instantly receives the asset in their wallet. Typically, the process takes no more than a minute. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://whitepaper.tanpin.io/technical-insights/payment-system.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.