I am using a FireBase Extension (PDFPlum) to capture the contents of new documents and convert them to a PDF file that is placed in a storage bucket. The process seems to be working, except for the fact that I am unable to download the file. Please see the screenshot below.
I think a file is only downloadable from the Firebase console by clicking on its name when a download URL exists for that file, and it sounds like the way you upload them doesn't create a download URL.
You'll want to check if the extension you use has an option to generate a download URL, or maybe file a feature request for it to (optionally) do so.