Ah if you don't understand this part (yet), read on how to use NPM package and NPM scripts. In short: you need to (probably) run npm install on the folder where the package.json is located. That installs the required NPM packages. It's a bit like NuGet. And in the same folder where the package.json is located, you need to run npm run build to actually build everything. That will output to the wwwroot folder and that will get picked up by your target project