I store various pdf in Proton Drive and Google Drive. I also have my own pdf viewer that I like to use to open pdf files. Please provide a feature that allows us to open files stored in Proton Drive with our own applications. Let me bring my own pdf viewer to the table like Google Drive does.

edit: Although, it seems Google's feature of this is really just a one click shortcut to download the file to the device and open it from there. But it all happens in one click.