Issue with Local storage setup when using External Storage application

I am trying to set up Local storage for a folder present on Ubuntu system using the External Storage application.

The Nextcloud instance I am using is installed on a domain( something like

Also, since there are a number of users within a company, I am one of the few who have full admin access to it. So, I installed the application and went forward to set up the local storage by giving the path to the directory which I wan to mount. But it does not mount for some reason. I also changed the permissions to the folder and it still shows as could not mount. This is what it shows:

Another problem is that I don’t have access to the system on which Nextcloud is installed. This means I cannot look into logs and stuff.

My guess is that I am not entering the Configuration properly. That said, I am using this path in this field: /home/ubuntu/Desktop_storage_test.

I also changed the permissions of the folder storage_test and it doesn’t work.

Should I add something before the path or do something else ?