try something like this:
var entity = {};
entity["customerid_account@odata.bind"] = "/accounts(9392B0D1-85FF-E611-8115-C4346BAC2AD8)"; //replace Guid
var req = new XMLHttpRequest();
req.open("POST", Xrm.Page.context.getClientUrl() + "/api/data/v9.0/incidents", true);
req.setRequestHeader("OData-MaxVersion", "4.0");
req.setRequestHeader("OData-Version", "4.0");
req.setRequestHeader("Accept", "application/json");
req.setRequestHeader("Content-Type", "application/json; charset=utf-8");
req.setRequestHeader("Authorization", "Bearer " + token); //Replace token with your token value
req.onreadystatechange = function() {
if (this.readyState === 4) {
req.onreadystatechange = null;
if (this.status === 204) {
var uri = this.getResponseHeader("OData-EntityId");
var regExp = /\(([^)]+)\)/;
var matches = regExp.exec(uri);
var newEntityId = matches[1];
} else {
Xrm.Utility.alertDialog(this.statusText);
}
}
};
req.send(JSON.stringify(entity));
