Cant get HDDs mapped to Nextcloud docker

Noob here; I already googled the issue but got stuck.

I have OMV 5 installed on a small SSD and two 4Gb HDDs.

What I want to achieve:

Use a folder within a volume for nextcloud.

What I have done so far:

1. Installed OMV-extras, Docker and Portainer

2. I installed the "b. local-persist" driver so I can use the (mirrored) HDDs on /dev/md0

Added Volume via SSH

docker volume create -d local-persist -o mountpoint=/dev/md0/nextcloud --name=nextcloud

3. Installed nextcloud and added the volume (mountpoint /nextcloud mount path /nextcloud)

After installing Nextcloud I get no error message, but the volume used is different

and shows the path /var/www/html

I am sure that the folder is created because I did something wrong, when creating the persistent volume.

Can you help a noob please?

Thank you very much.

Ok, so the solution is to create a volume in Portainer.

For mountpoint it is mountpoint

The path you can get by typing lsblk via SSH. There you see the paths of your disk drives.

For this path you can enter for instance /srv/dev-disk-by-label-storage/nextcloud

After this I created the nextcloud container, chose the newly created volume "nextcloud" and put in the path

/var/www/html

Obviously it was quite easy, but I misunderstood the information on some forums.