Works with a single dropbox account only.  
INSTALLATION

SETUP VIDEO:
https://youtu.be/MCtYHYUYUmk

This plugin requires a free dropbox API developer 'access token'.  Dropbox's sign-in process (more specifically, their implementation of OAuth2) does not seem to be supported by bubble at this time so only a single developer account is supported.

How to get a token:
(more detailed info can be found via web search)

(1) go to dropbox API developer site
(2) login with your dropbox account and create an 'app'.  The 'app' you've created is simply dropbox's way to allow API access to your dropbox account.
(3) inside your 'app' on the dropbox developer site, generate an access token for use with this plugin.  
 Notes:
 - This token supposedly lasts indefinitely, but can be manually revoked if you want.
 - You get 1 token per app. Regenerating your token, will revoke the old token.  

ADDING YOUR API KEY INTO THIS PLUGIN:
This plugin uses a 'Bearer' prefix, please read on below.

Please make sure your token looks exactly as follows:
Bearer <YOUR_ACCESS_TOKEN>

NOTE: Access Token (above)
Your access token must be generated and is NOT the secret key and should look similar to this:
fcJo7cIUZlAAAAAAAAAALH72bjiqveQuLjERR3p-Uq3JQlTArJYYWNKwBi2bYWYi

NOTE: API Call - Get Temporary Link
This returns a download link valid for 4 hours.  You may navigate to this link and to download.

NOTE: API Call - Download
* *Not working / experimental* *
- To download a file to the users browser use the 'Get Temporary Link' (shown above)
- The 'Download' call returns a FILE, not a download link. It doesn't seem to work with the bubble API connector and does not pass a download into the users browser. It may actually save to bubble S3, however the resulting S3 URL does not seem to be returned.