Thanks for your answer. My coworker and I have been combing this forum for over a week or so But we haven’t find and answer that could lead or point to the desired direction.
Also make sure you’re looking through not just the Admin Manual, but also the User Manual. The latter has more on things like file drops, anonymous uploads with file drops, etc. - e.g.
I suggest you play with the above a bit then expand out to evaluating the groupfolders app add-on to see what approach(es) make the most sense in your use case.
Install the group folders app and set up a group folder and group for the users who need access. Make a subfolder for each client. You’ll share these sub folders with the individual clients.
You can do a public link share with a password, can be a file drop or just give them full access to their folder, whatever you want to do there.
Or, you could install the guests app and give them actual guest accounts, still with access to just that shared folder. This is probably more secure because they can set their own password. You don’t have to send it to them.