You'll need to setup your persistent mappings in unRAID like the docker-compose example. I attached a screenshot showing my setup. Be sure to create an empty idrivecrontab.json file on you local system before starting the container. Use the touch command, (touch /mnt/user/appdata/idrive/etc/idrivecrontab.json) in a terminal.
All mappings are Read/Write with the exception of the backup_dir, that's set to Read Only.