ReactJS Library being used in NextJS project says is not a constructor

I have built a ReactJS library and published to NPM and works fine in a standard ReactJS project, but I now have a NextJS and I am trying to add it there, I expected it would just work as NextJS is a framework on top of ReactJS with some additional functionality.

In the app.js I have the following:

import dynamic from 'next/dynamic'
import {useEffect} from "react";

function MyApp({ Component, pageProps }) {

    const {CrashCatch, CrashCatchProvider} = dynamic(import('crashcatchlib-reactjs'), { ssr: false })

    let crash_catch = new CrashCatch();

    crash_catch.initialiseCrashCatch("12978650", "d7kqcewvshoyxbp564f8tm0zl", "1.0.1");

    return (
       ....
    ) 
}

When running this I get TypeError: CrashCatch is not a constructor

I have tried not using a dynamic import and doing a standard import as import {CrashCatch, CrashCatchProvider} from "crashcatchlib-reactjs"; but then I get the error SyntaxError: Cannot use import statement outside a module]

The source code for the reactjs library is open source so its available on GitHub at https://github.com/Crash-Catch/CrashCatchLib-ReactJS. The index.js has the class CrashCatch which has the constructor so not sure why NextJS is treating it differently.