How to update Seller Order Id with Amazon SP API

Question

I have been trying to update Seller Order ID with SP API Feeds API. But it is getting updated on sellercentral.

Bellow is my XML Feed Document:

<AmazonEnvelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="amzn-envelope.xsd">
<Header>
    <DocumentVersion>1.01</DocumentVersion>
    <MerchantIdentifier>123456789</MerchantIdentifier>
</Header>
<MessageType>Order</MessageType>
<PurgeAndReplace>false</PurgeAndReplace>
<Message>
    <MessageID>1</MessageID>
    <OperationType>Update</OperationType>
    <Order>
        <SellerOrderId>56789</SellerOrderId>
        <StandardOrderID>
            <Type>AmazonOrderId</Type>
            <Value>123-1234567-1234567</Value>
        </StandardOrderID>
    </Order>
</Message>

Answer 1

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">

<!--
$Date: 2005/04/01 $

AMAZON.COM CONFIDENTIAL.  This document and the information contained in it are
confidential and proprietary information of Amazon.com and may not be reproduced, 
distributed or used, in whole or in part, for any purpose other than as necessary 
to list products for sale on the www.amazon.com web site pursuant to an agreement 
with Amazon.com.
-->

<xsd:include schemaLocation="amzn-base.xsd"/>

<xsd:element name="OrderFulfillment">
    <xsd:complexType>
        <xsd:sequence>
            <xsd:choice>
                <xsd:element ref="AmazonOrderID"/>
                <xsd:element ref="MerchantOrderID"/>
            </xsd:choice>
            <xsd:element name="MerchantFulfillmentID" type="IDNumber" minOccurs="0"/>
            <xsd:element name="FulfillmentDate" type="xsd:dateTime"/>
            <xsd:element name="FulfillmentData" minOccurs="0">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element ref="CarrierCode" minOccurs="0"/>
                        <xsd:element name="CarrierName" type="String" minOccurs="0"/>
                        <xsd:element name="ShippingMethod" type="String" minOccurs="0"/>
                        <xsd:element name="ShipperTrackingNumber" type="String" minOccurs="0"/>
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>

            <xsd:element name="CODCollectionMethod" minOccurs="0">
                <xsd:simpleType>
                    <xsd:restriction base="xsd:string">
                        <xsd:enumeration value="DirectPayment"/>
                    </xsd:restriction>
                </xsd:simpleType>
            </xsd:element>

            <xsd:element name="Item" minOccurs="0" maxOccurs="unbounded">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:choice>
                            <xsd:element ref="AmazonOrderItemCode"/>
                            <xsd:element ref="MerchantOrderItemID"/>
                        </xsd:choice>
                        <xsd:element name="MerchantFulfillmentItemID" type="IDNumber"
                            minOccurs="0"/>
                        <xsd:element name="Quantity" type="xsd:positiveInteger" minOccurs="0"/>
                         <xsd:element name="TransparencyCode" type="xsd:string" minOccurs="0" maxOccurs="10"/>
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
            <xsd:element name="ShipFromAddress" type="AddressType" minOccurs="0" />

        </xsd:sequence>
    </xsd:complexType>
</xsd:element>

</xsd:schema>