Nextcloud Portainer External Storage

I’ve installed openmediavault with docker and portainer. Installed Nextcloud through portainer.
I have an external drive mounted in openmediavault that I can access with windows network.
On openmediavault the shared folder is
/srv/dev-disk-by-uuid-2A0B-54AD/Backup-Main
I want to be able to see the share folder in nextcloud external drive.
I tried to add the path in portainer under ‘volumes’ in the stack editor. But I still can’t see the contents of the folder or write to it.
I’m sure it’s something simple I’m overlooking.
I tried finding the bind function on the portainer webui, but I don’t see it.
Thank you