Installing via Azure Marketplace "nopCommerce" template: can't connect to db from /install screen

I used the "nopCommerce" Azure Marketplace tile to install last night.
The deployment ran just fine, installing SQL Server, Database, App Service and App Service Plan.
I am able to connect to the installation screen via the base URL (my site url/install)

BUT, I can't get the install screen to connect successfully to the SQL Server database the nopCommerce Azure template created.

I've tried a few different connection strings but I always get this error:
Setup failed: Database does not exist or you don't have permissions to connect to it

Do I need to configure virtual network and put all the resources that the marketplace template created in it?  Is there some other setup I need to do on the Azure portal side before the nopCommerce installation can connect to the database?

Figured it out (sort of).  Ended up trying a few things, but I think the thing that worked was to create a Service Connector in the App Service (web app).  Before that, I also made sure that virtual network was set up, but nothing seemed to work until I discovered Service Connector, ran the cloud shell script it generated, and harvested the connect string from the output of the cloud shell operation.

Hope that helps if anyone faces the same issue...