Building a Payment Token Request for Sell Orders
Sell orders require the following mandatory fields:

• bill_cardholder: the customer's unique ID
• bill_currencycode: similar to a Buy order, this parameter is now a supported cryptocurrency instead of fiat currency e.g. BTC
• target_currency: a supported fiat currency e.g. USD
• wallet_address: the address associated with the cryptocurrency being sold in the event that a refund is necessary
• returnUrl: used to return the customer to your website once the order is completed
• serverUrl:used to send webhooks when certain order statuses are reached.

The iframe_domain should be the exact domain that you will be using to host the iFrame e.g. binance.beta.io, and NOT your Banxa domain that was provided to you e.g. binance.banxa.com. Our CSP headers will then allow this frame-ancestor to be using Banxa checkout in an iFrame element.

Do not include https:// in front of the domain.