Unable to access Box folders and files via API with oauth2 Box App

Hello! 

I am trying to use the Box API to get my Box folders and folder items with an oAuth2 Box App. My user is either an Owner or Co-Owner of the folders I am trying to access.

I  am using the Client Id and Client Secret to get the access token from the auth URL and when I  use that in the request for the folder I  get an error saying, "Invalid value 'd_xxxxxxxxxxx0'. 'folder' with value 'd_xxxxxxxxxxx0' not found". Any help would be appreciated.