I cannot really comment on the .js except that if the original file is not modified, then it should work as expected on the exported site.
What kind of change did you make to the script if any?
What is the url of the exported site? Are there any messages in the browser console?
A good test is to download the export from Webflow, then unzip and open the site locally in Safari with no modifications made to the export files (or upload to server without modification). After that, check if the IX work ok without modification.
Thanks in advance.