Dynamics 365: Call global action with input and output parameters through JavaScript using XMLHttpRequest

1. I have created below action in dynamics 365.

2. new_CreatePerson action will create a new record for custom entity.

3.

4. Below is the JavaScript code to call the action.

var firstName;

var lastName;

function CreatePerson() {

    debugger;

    firstName = document.getElementById("firstName").value;

    lastName = document.getElementById("lasttName").value;

    var data =

    {

        "new_name": firstName + " " + lastName,

        "new_firstname": document.getElementById("firstName").value,

        "new_lastname": document.getElementById("lasttName").value

    }

    debugger;

    var req = new XMLHttpRequest();

    req.open("POST", Xrm.Page.context.getClientUrl() + "/api/data/v9.1/new_CreatePerson", 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.onreadystatechange = function () {

        if (this.readyState === 4) {

            req.onreadystatechange = null;

            if (this.status === 204) {

                debugger;

                var results = JSON.parse(this.response);

            }

            if (this.status === 200) {

                debugger;

                var results = JSON.parse(this.response).id;

                Xrm.Utility.alertDialog("Record created with name: " + results);

            }

            else {

                debugger;

                Xrm.Utility.alertDialog(this.statusText);

            }

        }

    };

    req.send(JSON.stringify(data));

}