I can't connect my Dropbox account with my NBDesigner plugin for WordPress. ... Should I create an application in a dropbox and make the correct settings for my site?(Do I need to embed the dropbox JS code on my site or is it unnecessary for my task?)
You'll have more luck reaching out to the developers on the NBDesigner plugin. They're the ones that would have built the code used to connect to your Dropbox, so only they will be able to support it. Dropbox cannot provide support for third-party applications.
I think that I didn't understand in dropbox enough for this, because from the side of the plugin(NBDesigner), only 2 things are required from me, which the dropbox should give me is the token and the path.