When you render a React component inside a modal handled by jQuery and would like to be able to handle closing it from there:

  className="button btn-cancel"

You can do this:

private handleClose = (ev: React.MouseEvent<HTMLInputElement>) => {

This works, but you will get an error from TypeScript compiler:

TS2339: Property '$' does not exist on type 'Window'.

You will need to extend the window interface with your new property:

declare global {
  interface Window { $: any } // 'any' isn't ideal but we all know what we have to deal with

window.$ = window.$ || {};