Named certificate '' not found API response XML signing and encryption

I am working on an integration which requires signing and encryption of the xml payload before passing it into the request content.

I am using java to sign and encrypt the xml document and this is what I get

<xenc:EncryptedData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#" Type="http://www.w3.org/2001/04/xmlenc#Element">
    <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"/>
    <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
        <xenc:EncryptedKey>
            <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-1_5"/>
            <xenc:CipherData>
                <xenc:CipherValue>I1ik...</xenc:CipherValue>
            </xenc:CipherData>
        </xenc:EncryptedKey>
    </ds:KeyInfo>
    <xenc:CipherData>
        <xenc:CipherValue>tTYZZ.....Vtl1WwQ==</xenc:CipherValue>
    </xenc:CipherData>
</xenc:EncryptedData>

Using the above payload the response is 401 Status code and the below xml

<?xml version="1.0" encoding="UTF-8"?>
<xenc:EncryptedData Type="http://www.w3.org/2001/04/xmlenc#Element" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
    <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"/>
    <dsig:KeyInfo xmlns:dsig="http://www.w3.org/2000/09/xmldsig#">
        <xenc:EncryptedKey Recipient="name:">
            <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-1_5"/>
            <dsig:KeyInfo>
                <dsig:KeyName/>
            </dsig:KeyInfo>
            <xenc:CipherData>
                <xenc:CipherValue>*Named certificate '' not found*</xenc:CipherValue>
            </xenc:CipherData>
        </xenc:EncryptedKey>
    </dsig:KeyInfo>
    <xenc:CipherData>
        <xenc:CipherValue>*Named certificate '' not found*</xenc:CipherValue>
    </xenc:CipherData>
</xenc:EncryptedData>

Which certificate exactly is this named certificate and how do I add this detail to my encrypted payload

// Sign the XML
        org.apache.xml.security.Init.init();
        ElementProxy.setDefaultPrefix(Constants.SignatureSpecNS, "ds");
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(true);
        Element root = xmlDoc.getDocumentElement();
        XMLSignature sig = new XMLSignature(xmlDoc, "file:", XMLSignature.ALGO_ID_SIGNATURE_RSA);
        root.appendChild(sig.getElement());
        Transforms transforms = new Transforms(xmlDoc);
        transforms.addTransform(Transforms.TRANSFORM_ENVELOPED_SIGNATURE);
        transforms.addTransform(Transforms.TRANSFORM_C14N_OMIT_COMMENTS);
        sig.addDocument("", transforms, Constants.ALGO_ID_DIGEST_SHA1);
        
        KeyInfo info = sig.getKeyInfo();
        X509Data x509data = new X509Data(xmlDoc);
        x509data.add(new XMLX509IssuerSerial(xmlDoc,signCert));
        x509data.add(new XMLX509Certificate(xmlDoc, signCert));
        info.add(x509data);
        
        sig.sign(privateSignKey);
        
        // Encrypt the XML
        String jceAlgorithmName = "DESede";
        KeyGenerator keyGenerator = KeyGenerator.getInstance(jceAlgorithmName);
        Key symmetricKey = keyGenerator.generateKey();
        String algorithmURI = XMLCipher.RSA_v1dot5;
        XMLCipher keyCipher = XMLCipher.getInstance(algorithmURI);
        keyCipher.init(XMLCipher.WRAP_MODE, publicEncryptKey);
        EncryptedKey  encryptedKey = keyCipher.encryptKey(xmlDoc, symmetricKey);
        Element rootElement = xmlDoc.getDocumentElement();
        algorithmURI = XMLCipher.TRIPLEDES;
        XMLCipher xmlCipher = XMLCipher.getInstance(algorithmURI);
        xmlCipher.init(XMLCipher.ENCRYPT_MODE, symmetricKey);
        EncryptedData encryptedData = xmlCipher.getEncryptedData();
        KeyInfo keyInfo = new KeyInfo(xmlDoc);
        keyInfo.add(encryptedKey);
        encryptedData.setKeyInfo(keyInfo);
        xmlCipher.doFinal(xmlDoc, rootElement, false);

Issues Resolved API required a query parameter of client id.