# Invoices - [Invoices concept](https://docs.txn.io/invoices/invoices-concept.md) - [Invoice integration guide](https://docs.txn.io/invoices/invoice-integration-guide.md) - [Invoice status flow](https://docs.txn.io/invoices/invoice-status-flow.md) - [Invoices in cashier](https://docs.txn.io/invoices/invoices-in-cashier.md) - [Listing invoice currency pairs](https://docs.txn.io/invoices/listing-invoice-currency-pairs.md) - [Invoice webhooks](https://docs.txn.io/invoices/invoice-webhooks.md) - [Creating invoice](https://docs.txn.io/invoices/creating-invoice.md) - [Reading invoice](https://docs.txn.io/invoices/reading-invoice.md) - [Listing invoices](https://docs.txn.io/invoices/listing-invoices.md) - [Invoice refunds](https://docs.txn.io/invoices/invoice-refunds.md) - [NFT invoice payment method integration guide](https://docs.txn.io/invoices/nft-invoice-integration-guide.md): This guide explains how to integrate the NFT invoice payment method with txn, from initial setup through successful payment confirmation. --- # 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://docs.txn.io/invoices.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.