You do not have permission to insert '' charts because the tenant is mounted with the application database as read-only. Contact your system administrator."
Can someone advice please what permissions to be updated for this ?
This is not a user permission issue. This error means that the tenant you are connected to is not allowed to write into the application database.
"Chart" is one of the tables belonging to the application database in multitenant environment, and by default, when a new tenant is mounted, it is not allowed to write into this DB.
A solution would be to identify a tenant that has the required permission and create the chart in that tenant. It's the one that has "Allow Writing to Application Database" option set to True.
If all of the tenants are mounted without that permission, create a new one (or dismount one of the existing and mount it back) with the key -AllowAppDatabaseWrite:
Mount-NAVTenant -ServerInstance BC130 -Tenant default -DatabaseName "Demo Database NAV (13-0)" -AllowAppDatabaseWrite