How to publish correctly JS externals

I am trying to test the JS part of my FirebaseMultiplatform library. But when using it inside a Kotlin/JS project the webpack errors with:

ERROR in D:/Progetti/Android-Application/build/js/packages_imported/firebase-multiplatform-auth/0.1.8/firebase-multiplatform-auth.js
Module not found: Error: Can't resolve 'firebase.auth.ActionCodeInfo' in 'D:\Progetti\Android-Application\build\js\packages_imported\firebase-multiplatform-auth\0.1.8'
 @ D:/Progetti/Android-Application/build/js/packages_imported/firebase-multiplatform-auth/0.1.8/firebase-multiplatform-auth.js 3:4-144
 @ ../my-application-kodein-di/kotlin/my-application-kodein-di.js
 @ ./kotlin/my-application-web-client-2.js
 @ multi ./kotlin/my-application-web-client-2.js

Now, firebase.auth.ActionCodeInfo is actually a class from the official Firebase JS library for which Dukat wrote this (that i rearranged into packages).

Why does this infernal webpack machinery looks for it inside my library instead of the Firebase one?

Issue for reference: https://youtrack.jetbrains.com/issue/KT-36427