ContactKey is required error when firing Event (Interaction Event)

Question

1. I have successfully get access token via ssjs
2. When passing it to POST /interaction/v1/events (https://developer.salesforce.com/docs/atlas.en-us.noversion.mc-apis.meta/mc-apis/postEvent.htm) i'm getting error message "ContactKey is required"

SSJS Post Request:

var payload = {
            ContactKey: subscriberKey,
            EventDefinitionKey: EventDefinitionKey,
            EstablishContactKey: true, 
            Data: { 
                EmailAddress: emailAddress
            }
        }
        var url = 'https://www.exacttargetapis.com/interaction/v1/events';
        var auth = 'Bearer ' + accessToken;

        var req = new Script.Util.HttpRequest(url);
        req.emptyContentHandling = 0;
        req.retries = 2;
        req.continueOnError = true;
        req.contentType = "application/json"
        req.setHeader("Authorization", auth);
        req.method = "POST";
        req.postData = payload;

        var resp = req.send();

Sample Request:

{
    "ContactKey":"test@email.com",
    "EventDefinitionKey":t"APIEvent-xxx",
    "Data": {
        "field1":"value1" 
    }
}

Sample response:

{
    "message": "ContactKey is required.",
    "errorcode": 10000,
    "documentation": ""
}

Why I'm getting that error message? Any help would be appreciated.

Answer 1

Use proper id posting request example here. {"EventDefinitionKey":"APIEvent-ba299b28-102a-d953-09bd-09bdf8e117e6","ContactKey":"ID601"}