Hooks Storage :Cannot attach, storage is singular

Hello ,

I’m trying to attached a new storage for my charm that is deployed locally and i have added below details to metadat.yaml file :

storage:
data:
type: file
description: junk storage
shared: false
read-only: false
minimum-size: 100M
location: /home/duaa/Documents

but i’m getting this error while attaching the defined storage to my charm :