Hello @jackie.tian2,
I'm not sure the DNS domain name can be set this way. Please see pages 11-12 in this PDF for the list of configurations you can change, as well as an example:
Webex Room Device APIs: The power of automated, integrated, immersive collaboration
https://www.ciscolive.com/c/dam/r/ciscolive/emea/docs/2020/pdf/DEVNET-1462.pdf
Here are the only other examples I could find:
Example 1: Changing the device name
Request
POST /putxml HTTP/1.1
Content-Type: text/xml
<Configuration>
<SystemUnit>
<Name>newName</Name>
</SystemUnit>
</Configuration>
Example 2: Setting the camera position
Request
POST /putxml HTTP/1.1
Content-Type: text/xml
<Command>
<Camera>
<PositionSet command=”True”>
<CameraId>1</CameraId>
<Pan>200</Pan>
<Tilt>200</Tilt>
</PositionSet>
</Camera>
Example: Registering feedback on configuration changes,
disconnect events and call status changes.
POST /putxml HTTP/1.1
Content-Type: text/xml
<Command>
<HttpFeedback>
<Register command=”True”>
<FeedbackSlot>1</FeedbackSlot>
<ServerUrl>http://127.0.0.1/myhttppostscripturl</ServerUrl>
<Format>XML</Format>
<Expression item=”1”>/Configuration</Expression>
<Expression item=”2”>/Event/CallDisconnect</Expression>
<Expression item=”3”>/Status/Call</Expression>
</Register>
</HttpFeedback>
</Command>
source: https://www.cisco.com/c/dam/en/us/td/docs/telepresence/endpoint/ce913/collaboration-endpoint-software-api-reference-guide-ce913.pdf