The following command modifies the existing addedfqdn.com FQDN to set the selectioncriteria to Weighted Round Robin (WRR):

curl -k "https://bal:1fourall@20.200.25.100/access/modfqdn?fqdn=addedfqdn.com&selectioncriteria=wrr"

Response: 

<?xml version="1.0" encoding="ISO-8859-1"?>
<Response stat="200" code="ok">
<Success><Data><fqdn><Status>Up</Status>
<FullyQualifiedDomainName>addedfqdn.com.</FullyQualifiedDomainName>

<SelectionCriteria>wrr</SelectionCriteria>

<FailTime>0</FailTime>
<SiteRecoveryMode>auto</SiteRecoveryMode>
<Mapping>0</Mapping>
<failover>N</failover>
</fqdn></Data>
</Success>
</Response>