In order to receive Server Monitoring Resource Usage webhook notifications, you will need to have the following:

Once you’ve got all of that configured, whenever you receive Resource Usage alerts, your Webhook URL will receive JSON format data, as well.

Here’s an example of a CPU Usage warning Webhook notification:

   "monitor_name":"Test Monitor Label",

Understanding the parameters:
monitor_id – your monitor’s unique ID (can be found in the link of your monitor’s uptime report);
monitor_name – the label of your uptime monitor;
timestamp – is the unix time stamp at which the event occurred;
resource_type – describes which resource type this notification is about (can be: cpuramdisknetwork_inboundnetwork_outbound);
current_usage – the current usage (percent) for this server monitor (i.e.: the usage taken the same minute the notification is sent out);
average_usage – the average usage (percent) over average_minutes minutes (based on your resource usage warning configuration).