Converting PDF to EPUB file.
You have your Kindle and you just downloaded the PDF, all you got to do is simply convert PDF to Kindle format.
The PDF is, however, on your cloud, so why would you have to download it from google drive, only to upload it again to the web app e.g. convertio
This is absolutely unnecessary and I wish somebody someday will build such an app, so I will just hold the file for a second in a cache and then automatically upload it to the web app.