How do I use "window.Twitch.ext" in angular for using the Configuration Service?

I have installed the package. I will need to import methods right?
Is there a documentation for the same?
Because, Even after installing the package I am getting the error

Element implicitly has an 'any' type because index expression is not of type 'number'.
twitch = window['Twitch'].ext;

I think that import { Twitch } from '@types/twitch-ext'; should just work and allow you to ditch the dep on window (by using it as Twitch.ext....), I am not overly sure on it since I’ve never used the twitch ext in ts.
I also think that you’re getting a warning instead of an error here.

It’s not working, I think the reason might be because ‘@types/twitch-ext’; is not a module.

Even just importing the package on runkit is giving Error: Cannot find module '@types/twitch-ext'.

I looked through the code of the package and they are missing an export statement.

Add declare let Twitch: any; at the top with the imports and then we can access all the methods with Twitch.ext