Embed documents from SharePoint in external Django application

What I want to achieve is to have a document viewer for PDF and Word documents in my own application, which is developed using Django. The requirements are:

• PDF and Word documents must remain on the SharePoint tenant, so I dont want to download the documents and then embed those in my application.

• I can setup an API with access to the SharePoint tenant, preferably with the Site.SelectedScope permission.

Over the past few weeks I have done a lot of research and found several forum questions, tutorials and blogposts but unfortunately I haven't found the solution yet. Therefore my question: does anyone know how I can achieve this?