How to add button control on Azure DevOps workitems page

Question

I am developing an Extension to add Button control that shows an HTML popup when the button is clicked.  I am following this link https://developer.microsoft.com/en-us/azure-devops/components/button#basic-buttons.

import * as React from "react";
import { Button } from "azure-devops-ui/Button";
import { ButtonGroup } from "azure-devops-ui/ButtonGroup";

Sample mock-up of what I want to achieve: 

On click of the Submit button following pop up has to be shown

When the user enters the details, the user name has to be filled in the User Name field in the first window.

Do pls suggest whether it is possible to add design as shown using AzureDevOps Extension on the workitem page?