Use this, replacing 192.168.1.4:8089
with the IP:Port
of your DVR Server
curl -s -XPOST http://192.168.1.4:8089/providers/m3u/sources/SamsungDocker/refresh
You can verify in the DVR log that it refreshes the lineup when that curl command is used.
[M3U] Refreshed lineup for SamsungDocker
If you want to discover these commands on your own, use your browser network inspector tool to see what commands are sent to the server.