Error using in typescript file - Uncaught TypeError: window.BotUI is not a constructor

[IsaacHub]

Throws the following error while using in typescript(.ts) file

I'm using this plugin with parcel-bundler.
index.html

<script src="app.ts"></script>

app.ts

import _botui from 'botui';

declare global {
  interface Window {
    BotUI: any
  }
}

let botui = new window.BotUI('bot', {
  vue: Vue
});

I have tried all possible combinations, and getting same error. But works in .js file

[IsaacHub]

This can be resolved if parcel allows to exclude botui library from processing bundle.
Unfortunately there is no way of excluding imported files from being bundled in parcel. But using <script> tag we can exclude from bundling with the help of another parcel helper plugin

It works fine while importing in .js file, there's something with the way parcel handles typescript. Or botui is not made for typescript + parcel combo? Other utility/third party libraries are working fine with typescript + parcel.