Create Invoice Request
data class CreateInvoiceRequest(val collectionMethod: InvoiceCollectionMethod, val netTerms: Int?, val lineItems: List<LineItem>?, val customer: String? = null, val account: String? = null, val dueDate: String? = null, val number: String?, val description: String?, val memo: String?, val metadata: Map<String, String>?)
Request body for creating a new invoice.