How to append url parameters in Wso2 API Manager

Appending url parameters in Wso2 API Manager using custom sequences:

 

<sequence xmlns="http://ws.apache.org/ns/synapse" name="eCommerce--Aria-add-params--In">

    <property name="REST_URL_POSTFIX" expression="fn:concat(get-property('axis2','REST_URL_POSTFIX'), '&amp;auth_key=mps8qpVB6NwjPgPGMJCNnAGKvHxNDbaX')" scope="axis2" type="STRING"/>

    <property name="REST_URL_POSTFIX" expression="fn:concat(get-property('axis2','REST_URL_POSTFIX'), '&amp;client_no=4974461')" scope="axis2" type="STRING"/>

    <log level="full">

        <property name="TRACE" value="Adding url params by Rajakrishna Reddy"/>

    </log>

</sequence>