Getting Started with the XML Gateway

Good day
i was trying to connect to the XML with below XML Data

<GovTalkMessage xmlns="http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#" xmlns:gt="http://www.govtalk.gov.uk/schemas/govtalk/core" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader http://xmlgw.companieshouse.gov.uk/v1-0/schema/Egov_ch.xsd">
<EnvelopeVersion>1.0</EnvelopeVersion>
<Header>
    <MessageDetails>
        <Class>NameSearch</Class>
        <Qualifier>request</Qualifier>
        <TransactionID>123</TransactionID>
        <GatewayTest>true</GatewayTest>
    </MessageDetails>
    <SenderDetails>
        <IDAuthentication>
            <SenderID>md5 value of sender id</SenderID>
            <Authentication>
                <Method>MD5SIGN</Method>
                <Value>md5 vale of Authentication Value</Value>
            </Authentication>
        </IDAuthentication>
        <EmailAddress>technical@*******.co.uk</EmailAddress>
    </SenderDetails>
</Header>
<GovTalkDetails>
    <Keys/>
</GovTalkDetails>
<Body>
    <NameSearchRequest xmlns="http://xmlgw.companieshouse.gov.uk/v1-0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlgw.companieshouse.gov.uk/v1-0/schema/NameSearch.xsd">
        <CompanyName>Sure Formation</CompanyName>
        <DataSet>LIVE</DataSet>
        <SameAs>0</SameAs>
        <SearchRows>20</SearchRows>
    </NameSearchRequest>
</Body>

RESPONSE

    <?xml version="1.0" encoding="UTF-8" ?>
<GovTalkMessage xsi:schemaLocation="http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader http://xmlgw.companieshouse.gov.uk/v1-0/schema/Egov_ch.xsd" xmlns="http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#" xmlns:gt="http://www.govtalk.gov.uk/schemas/govtalk/core" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
    <EnvelopeVersion>1.0</EnvelopeVersion>
    <Header>
        <MessageDetails>
            <Class>NameSearch</Class>
            <Qualifier>error</Qualifier>
            <TransactionID>123</TransactionID>
            <GatewayTest>true</GatewayTest>
            <GatewayTimestamp>2020-12-17T13:54:03-00:00</GatewayTimestamp>
        </MessageDetails>
        <SenderDetails>
            <IDAuthentication>
                <SenderID>*********</SenderID>
                <Authentication>
                    <Method>CHMD5</Method>
                    <Value>***********</Value>
                </Authentication>
            </IDAuthentication>
            <EmailAddress>technical@********.co.uk</EmailAddress>
        </SenderDetails>
    </Header>
    <GovTalkDetails>
        <Keys/>
        <GovTalkErrors>
            <Error>
                <RaisedBy>NameSearch</RaisedBy>
                <Number>502</Number>
                <Type>fatal</Type>
                <Text>Authorisation Failure</Text>
                <Location></Location>
            </Error>
        </GovTalkErrors>
    </GovTalkDetails>
    <Body>
  </Body>
</GovTalkMessage>

Are you testing or trying to access live data?. in any event, these fields need to be completed and MD5# converted.
md5 value of sender id

MD5SIGN
md5 vale of Authentication Value
SDN