Alternatives to Java applet to launch Microsoft Office applications

In our web application, we used to use a Java applet to invoke MS. Office applications e.g. Word to open, edit, and save back a file to the server.

Google Chrome will no longer support NPAPI, so soon we can not run our applet in Chrome anymore. Plus, it seems that MS. Edge is not willing to support Java.

So, any suggestions for an alternative for the Java applet. We want to make the same experience for the user, just like before: we do not want to open the files in the browser.

I have also tried Html5 features e.g. FileSystem API. But, it turned out to me that at least that feature cannot help me. (to my knowledge, maybe I am missing something)

Thank you very much for your suggestions in advance.

Reza