One-time setup. Create a free app at dropbox.com/developers/apps (Scoped access, App folder or Full Dropbox), tick the permission files.content.write, and add the address below as a Redirect URI.
On an iPhone the home screen app and Safari keep separate settings. Connect in Safari, tap "Copy connection code", then open the home screen app and paste it below.
One name per line. They must match your workbook, or the import will skip those lines.