Xpath query to get the uuid from preview node

Experience Manager (PaaS/OnPrem)
1

Hi,
I want to take preview page uuid from preview node(myproject-preview) by page name ‘testpage’
My node path is " [/hst:hst/hst:configurations/myproject-preview/hst:workspace/hst:sitemap/testpage] "
Can you please help me by sending the xpath query for getting the page uuid by passing the page name from the preview node.

Thanks !

2 
final Query query = session.getWorkspace().getQueryManager().createQuery("/jcr:root/hst:hst/hst:configurations/myproject-preview/hst:workspace/hst:sitemap/testpage", Query.XPATH);
final QueryResult result = query.execute();
final String nodeId = result.getNodes().nextNode().getIdentifier();