I've not used the script before (try not to rely on cloud services much now) but you have to run the config wizard first to create the hidden ~/.dropbox_uploader with the details in.
I would delete this file:
rm ~/.dropbox_uploader
Run the program again (with NO parameters) using
./dropbox_uploader.sh
This will give you a set of instructions and a URL to link your account (see code here if you are concerned) about this.
Then run the program to check its linked to your account using
./dropbox_uploader.sh info
Sorry - it took me a bit longer than a day to set up another Pi - I needed to sort one and they where a bit tied up (whoops).
The process is as follows (personal account - not corporate):
- Pi Zero W v1.1 board connected via USB to my Mac
- Mac connected to the Internet via WiFi (though irrelevant for this)
- Clean install of Buster Lite (2020-02-13) updated as of today (20/04/20)
- Software downloaded from GitHub using the Curl option as per here and chmod to executable
- Dropbox account signed in. I then removed all devices from my account and cleared any old session (inc one from 2016 whoops) via Account/Security
- Apps list checked - Only Outlook enabled as an application via Account/Connected Apps
- Ran
./dropbox_uploader.sh
till it prompted me for the Access token
- In a new browser tab (still with the account tab open) I went to the given URL and selected Dropbox API, Full Dropbox and named the App 'Pi test on Outlook Account', agreed the T&Cs and pushed 'create app'
- On the next page I saw the App key / App secret pair - THIS IS NOT THE KEY YOU ARE LOOKING FOR
- Select the button under OAuth 2 / Generated access token labeled Generate

- This will then change into a 64 character long key and THIS IS THE KEY FOR THE PI (note mine is much longer than this):

After confirming the key looks OK the script reported it had been saved. ls -a
shows the hidden config file as above.
I was then able to run ./dropbox_uploader.sh info
and got (I redacted some of the data)
Name: Andrew B******
UID: dbid:************
Email: andrew******@outlook.com
Country: GB
Running ./dropbox_uploader.sh list
gave me
> Listing "/"... DONE
[D] Application Files
[D] Photos
[D] Camera uploads
[D] History Files EXCLUDING Lincoln
[F] 246779 File 03-12-2016, 03 17 23.jpeg
[F] 190763 File 03-12-2016, 03 18 03.jpeg
[F] 249428 File 03-12-2016, 03 18 23.jpeg
This matches the web view of the data fine. (Yes - it was really 2016 since I last used this.)
tl;dr:
- Make sure your Dropbox account is valid and not reached maximum APPLICATIONS.
- The Pi does not register as a device on Dropbox only an app so you can still have three computers AND a Pi or two...
- Simple app testing (info / dir / download / upload / delete) works under Buster
- Do not use the app secret / key
- Generate the OAuth 2 / Generated access token