Creating a volume - Getting error

When I go to the Create Volume web page I configure as follows:

Name: calibre-ebooks
Driver: Local
Driver Options: NAME: mountpoint VALUE: /volume1/ebooks

I then push the button to create the volume and get the following error

Create calibre-ebooks, invalid option key, “mountpoint”

What option should i use. I literally tells me to use mountpoint in the example. And I can’t find any documentation that tells me what the valid NAME values are.

I’m running Docker-ce on an Asustor NAS.
Engine Details

Version 18.06.3-ce (API: 1.38)
Root directory /volume1/.@plugins/AppCentral/docker-ce/docker_lib
Storage Driver overlay2
Logging Driver json-file
Volume Plugins local
Network Plugins bridge, host, macvlan, null, overlay

I have attached a screenshot of the error. Any assistance would be awesome.

volume page is for creating named volumes, not bind mounts… are you trying to use this to create a bind mount for calibre-ebooks to /volume1/ebooks? If so, you dont use the volumes page for that… when deploying a container, you scroll down to volumes, click on add volume, then select bind mount. in the container you put the path you want it to appear as, and then on the host put /volume1/ebooks