> Portal Navigation: > > - Append `.md` to any URL under `https://dev.wix.com/docs/` to get its markdown version. > - Pages are either content pages (article or reference text) or menu pages (a list of links to child pages). > - To get a menu page, truncate any URL to a parent path and append `.md` (e.g. `https://dev.wix.com/docs/sdk.md`, `https://dev.wix.com/docs/sdk/core-modules.md`). > - Top-level index of all portals: https://dev.wix.com/docs/llms.txt > - Full concatenated docs: https://dev.wix.com/docs/llms-full.txt ## Resource: wix-billing-backend ## Article: Introduction ## Article Link: https://dev.wix.com/docs/velo/apis/wix-billing-backend/introduction.md ## Article Content: # Introduction The Wix billing API allows you to manage billing of your customers, using invoices and price quotes. Learn more about how you can [create and manage invoices](https://support.wix.com/en/article/wix-invoices-about-wix-invoices) and [create and manage price quotes](https://support.wix.com/en/article/wix-price-quotes-creating-and-sending-price-quotes-to-clients). With the Wix billing APIs, you can: - Manage [invoices](/invoices/introduction). - Manage [price quotes](/price-quotes/introduction). - Create custom handling in response to backend [invoice events](wix-billing-backend/events/introduction). - Create custom handling in response to backend [price quote events](wix-billing-backend/events/introduction). To use the Wix billing APIs, import `wixBillingBackend` from the `wix-billing-backend` module: ```javascript import wixBillingBackend from 'wix-billing-backend'; ``` ## Before you begin It’s important to note the following points before starting to code: Invoices is an online payment request system and not an accounting service. In order to accept payments from customers in Wix Invoices, you must set up a [payment method](https://support.wix.com/en/article/accepting-payments-an-overview). ## Terminology - **Price Quotes**: Wix Price Quotes allows you to send professional price quotes to potential customers. You can convert price quotes into invoices. - **Invoices**: Wix Invoices is a payment request system which allows you to create, send, track and manage invoices (requests for payment), as well as receive payments online.