A simple Angular 7 application builded with eirslett/frontend-maven-plugin, in this example I have used a base configuration but for additional details we can visit the official plugin repository front-end-maven-plugin.
If we are behind a proxy, we can activate proxy configuration for do this is very easy, all that you need is set attribute:
<configuration>
<npmInheritsProxyConfigFromMaven>true</npmInheritsProxyConfigFromMaven>
</configuration>
mvn clean install
The directory dist contains the angular app builded, ready to deploy.