[api] Buying webHosting

Hello,
I'm trying to buy a webHosting throught OVH API. I'm using these
steps to do so :
'/order/cart/{cartId}/webHosting' with parameters (duration => P1Y,planCode => perso2014, pricingMode => default, quantity => 1)
'/order/cart/{cartId}/checkout' with parameters (waiveRetractationPeriod => false)
'/me/order/{orderId}/payWithRegisteredPaymentMean' with parameters
(paymentMean, paymentMeanId)

But I have a 400 HTTP Error for the second step with the message
Client::BadRequest,message: Missing "webhosting_domain" (or
"legacy_domain") configuration.

Do you know why I had this error ?

Thanks in advance