The release notes for vaadin 14 show an example of embedding a vaadin app in another site.
The documentation shows the WebComponentExporter as a interface:
public class ExpertChatExporter implements WebComponentExporter<ExpertChatComponent> {
public ExpertChat() {
super("expert-chat");
addProperty("user-context", null).onChange(ExpertChatComponent::onUserBrowsingContextChange);
}
}
WebComponentExporter is actually a class.
The doco is also inadequate.