{
    "ContactKey": "ID601",
    "EventDefinitionKey":"AcmeBank.AccountAccessed",
    "EstablishContactKey": true,
    "Data": {
        "accountNumber":"123456",
        "patronName":"John Smith"
    }
}

%%[
    Var @body, @callstatus, @response
    /* add your desired request-body to this variable */
    Set @body = '{"ContactKey": "YourKey"}'

    HTTPPost2("https://auth.exacttargetapis.com/interaction/v1/events", "application/json", @body, True, @callstatus, @response)

    IF @callstatus == 200 THEN
]%%

<p>Success!</p>

%%[
    ENDIF
]%%