How to inject external JS to Jest unit testing?

I want to test an external JS file using JEST.

I have created a setup file (setupExternalFile.js) that includes

global.ExtTest= require('https://test.com/externalJS.js');

In my App.test.js I have

import { hello } from './App';
import { ExtTest } from './setupExternalFile';

I am getting an error 'Cannot find module'

Thanks for your help.