Switch to the ClientApp folder:
cd C:\Users\Administrator\AWS-workshop-assets\northwind-traders
cd Src\WebUI\ClientApp
Run the following command to install all required Node.js modules:
npm install
Next build client Angular application by running the following command:
npm run-script build
Next open Northwind.sln file in Visual Studio 2019 or JetBrains Rider and build it as usual.