Using saved tokens

I've been trying to make an R package that uses `rdrop2` to access a private shared folder on Dropbox. Everything works fine when I'm working interactively, using credentials stored by `drop_acc()`. However I've been trying to pass in my token (as described in the README). However I keep getting an error: `File not found on Dropbox`.
Not sure if I am misusing the token, or if this error message is misleading.

Start with the README instructions for passing a saved token and compare them with interactive use of drop_acc(). Reproduce the private shared-folder access and determine whether the token handling causes the “File not found on Dropbox” error; done means the documented token workflow works or the failure is reported accurately.

Written by the indexing model from the issue text.