Can you try below command curl -i -k -X POST -H "Content-Type: application/json"  -d '{"Destination": "https:// ", "Protocol" : "Redfish", "EventTypes": ["Alert"], "Context": "Public"}' -u : 'https:// /redfish/v1/EventService/Subscriptions' –v  To perform Subscription, below properties are required. 
Have looked for any info on how to add a subscription for the EventService in idrac via curl or through REST plugin to web browser. Have both idrac8 and idrac9 servers, R730XD and R740XD Don't know what syntax to use. Have tried this curl POST, but are missing data about protocol , etc curl -i -k -X POST -H "Content-Type: application/json"  -d '{"Destination": "[URL]", "Protocol" : "odata"}' 'root:XXXX[NAME]-XXX.xxx.se/.../Subscriptions' -v Get HTTP/1.1 400 Bad Request "The value odata for the property Protocol is not in the list of acceptable values." Have tested http/https/TLS/odata as protocol name, what is missing ??
How to add Subscription for EventService with curl