How to create threshold alarm notification mail for bandwith cpu usage and memory usage in opennms

Please help me out to create threshold notification for cpu usage bandwith and memory utilization in opennms version 27.0.2

I would start with these videos:
Thresholds: OpenNMS 101 - Module 12: Thresholds - YouTube
Notifications: OpenNMS 101 - Module 4-1: Notifications - YouTube