It should work.
You can check this link for more information
https://developer.cisco.com/codeexchange/github/repo/robertcsapo/cisco-dnac-platform-webex-notifications/.
Basically I would do a simple test by sending the event trigger to a rest server first, like using https://webhook.site/ .
This is an example of JSON sent by DNAC. I configured the destination to https://webhook.site/...........
then reboot my router to get the trigger.
{
"version": "1.0.0",
"instanceId": "913886ef-8529-424c-a2ef-83697b43da21",
"eventId": "NETWORK-DEVICES-2-202",
"namespace": "ASSURANCE",
"name": null,
"description": null,
"type": "NETWORK",
"category": "ERROR",
"domain": "Know Your Network",
"subDomain": "Devices",
"severity": 2,
"source": "ndp",
"timestamp": 1682360732572,
"details": {
"Type": "Network Device",
"Assurance Issue Details": "Network Device csrv1000 is rebooting.",
"Assurance Issue Priority": "P2",
"Device": "10.xxx.xxx.xxx",
"Assurance Issue Name": "Device has rebooted due to a hardware or software crash",
"Assurance Issue Category": "Device",
"Assurance Issue Status": "active"
},
"ciscoDnaEventLink": "https://10.xxx.xxx.xxx/dna/assurance/issueDetails?issueId=913886ef-8529-424c-a2ef-83697b43da21",
"note": "To programmatically get more info see here - https://<ip-address>/dna/platform/app/consumer-portal/developer-toolkit/apis?apiId=8684-39bb-4e89-a6e4",
"context": null,
"userId": null,
"i18n": null,
"eventHierarchy": null,
"message": null,
"messageParams": null,
"parentInstanceId": null,
"network": null,
"dnacIP": "10.xxx.xxx.xxx"
}