Embed Office 365 preview/edit into my web app

Question

I'd like to give the option for users in my app to preview/edit excel files in an iframe. The files are stored and managed by my backend. This has already been accomplished by Autodesk construction cloud (BIM 360 Docs), but it is not clear to me how this is implemented. More information about the integration by Autodesk is available here. I would like to create a similar experience but need some direction as to how to start. Any help would be appreciated :)