Setting Department via API

Hello -

I'm looking to set the "Department" of a request via the API. I've tried adding the department with this endpoint, sdpapi/request?OPERATION_NAME=ADD_REQUEST and the following XML

<Operation>
<Details>
<parameter>
<name>requester</name>
<value>Requester</value>
</parameter>
<parameter>
<name>subject</name>
<value>Request Title</value>
</parameter>
<parameter>
<name>description</name>
<value>Body</value>
</parameter>
<parameter>
<name>department</name>
<value>DName</value>
</parameter>
</Details>
</Operation>

but yet the department remains blank, everything else adds correctly, but the department is empty. I verified the Department exists in Service Desk, but still no luck.

I've also tried adding the department at the "EDIT_REQUEST" endpoint with this XML
<Operation>
<Details>
<parameter>
<name>department</name>
<value>DName</value>
</parameter>
</Details>
</Operation>

Hopefully someone can point me in the right direction! Thanks!