We have a .NET core app with an angular project located at http://domain.com/webapp
Then we have to build the angular project like this:
ng build --base-href=/webapp/ --deploy-url=/webapp/
The --base-href is for the <base href="/webapp/"/> it must be set or else all API calls will be directed to the /
The --deploy-href is for the internal angular references, such as loading data from the assets folder.