Editing through Dropbox?


A few days ago, I’ve got the offer to work on a temporary freelance gig at an entry level, which is to do inbetween drawings for a collaborative project.
But there’s one condition in order to follow their pipeline, and that is having to open up the file through a cloud drive, mainly Dropbox. No downloading, updating and replacing.

So after they sent me a test along with guidelines that requires to do so, I’ve followed it by opening it up from there with Harmony 20.
But as it opened, I saw that the frames are not shown up in the display area.

I’ve tried everything in the file to get it to show up, only to realize that it only works when I download it off from Dropbox and open it up from my own computer.
I contacted then asking if they can fix it or just reconsider to download it instead, but then soon after I got turned down in the reply saying that following the pipeline is part of their test and I’m not able to work for them because of that.

I was torn by that reply, since this type of job that I’ve aimed for is simply rare nowadays and also a bit mad because they’re not letting to help me with this problem.
I’m still not sure if they’re able to pull it off by editing it directly in a cloud drive whether if it’s true or not.

So I’m here to urgently ask you all this: Is it possible to edit a TBH20 file in Dropbox?
I’ll be open to any replies that are clearly helpful.

Kind regards.