How to set trackingUrlTemplate in CustomerService?

[fp.mm...@gmail.com]

I'm trying to set TrackingUrlTemplate and I getting the error in response. I know that you do not support JS but I'm doing it through javascript using node-adwords. 

If you be so kind and give me a sample of php code how to do mutate() on CustomerService then I could figure out how to do it with JS.

I don't know what customers fields are required for mutate().

I have read almost every guide and code sample on you dev site. But can't find any example of mutate for CustomerService.

Thank you in advance! Really hope some one can help!

<soap:Envelope

xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">

<soap:Header>

<ResponseHeader

xmlns:ns2="https://adwords.google.com/api/adwords/cm/v201809"

xmlns="https://adwords.google.com/api/adwords/mcm/v201809">

<ns2:requestId>00057a7858a439180a8585977b036599</ns2:requestId>

<ns2:serviceName>CustomerService</ns2:serviceName>

<ns2:methodName>mutate</ns2:methodName>

<ns2:operations>1</ns2:operations>

<ns2:responseTime>162</ns2:responseTime>

</ResponseHeader>

</soap:Header>

<soap:Body>

<soap:Fault>

<faultcode>soap:Server</faultcode>

<faultstring>[RequiredError.REQUIRED @ customer]</faultstring>

<detail>

<ApiExceptionFault

xmlns="https://adwords.google.com/api/adwords/mcm/v201809"

xmlns:ns2="https://adwords.google.com/api/adwords/cm/v201809">

<ns2:message>[RequiredError.REQUIRED @ customer]</ns2:message>

<ns2:ApplicationException.Type>ApiException</ns2:ApplicationException.Type>

<ns2:errors

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ns2:RequiredError">

<ns2:fieldPath>customer</ns2:fieldPath>

<ns2:fieldPathElements>

<ns2:field>customer</ns2:field>

</ns2:fieldPathElements>

<ns2:trigger></ns2:trigger>

<ns2:errorString>RequiredError.REQUIRED</ns2:errorString>

<ns2:ApiError.Type>RequiredError</ns2:ApiError.Type>

<ns2:reason>REQUIRED</ns2:reason>

</ns2:errors>

</ApiExceptionFault>

</detail>

</soap:Fault>

</soap:Body>

</soap:Envelope>