Unable to receive notifications subscribed through xpath

I cannot receive a reply after subscribing.The API is confd_notification_send().

No reply can be received using the following message:
<create-subscription xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0"> <filter type="subtree"> <test:alarm-notif xmlns="urn:test:alarm:1.0"/> </filter> </create-subscription>

But I can receive a reply using the following message
<create-subscription xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0"> <stream>alarm-notif</stream> </create-subscription>

The first create-subscription message does not contain the stream name, which means the base notification stream “NETCONF” is used instead.