Spring Boot Reactive OAuth2 with JWT

Question

I am currently developing an application with SpringBoot 2.0.0.M7 and spring-boot-starter-webflux. It also use Spring Boot WebFlux Functional Rest API and Spring Boot Actuator.

Application itself is very simple and it works as expected. I can POST book (/api/v1/book) to the ArrayList and GET all books (/api/v1/book) from ArrayList. Rest API Documentation is available on (/) URL and Actuator endpoint is available on (/actuator) URL.

Problem is that how can I secure my WebFlux Functional Rest API with OAuth2 and JWT? I can find many examples OAuth2 with JWT but they are for older Spring Boot. Here is one example https://dzone.com/articles/spring-oauth2-with-jwt-sample SpringBoot 2.0.0.M7 has a support on OAuth2 Login but this example https://spring.io/blog/2017/09/15/spring-security-5-0-0-m4-released does not tell how to use OAuth2 with JWT in a Rest API. I did not even find a full source code of that example. This video https://www.youtube.com/watch?v=LzNhedHo7pM and this example https://medium.com/@mohitsinha.it/spring-boot-reactive-tutorial-ffab309b2dcd will only use a basic authentication.

Does anyone know how I can secure my (/api/v1/book) endpoint using @EnableWebFluxSecurity annotation and OAuth2 with JWT?

Below has example on my RoutingConfiguration class.

@Configuration
@EnableWebFlux
public class RoutingConfiguration implements WebFluxConfigurer {

    private final static String API_URL = "api";
    private final MeterRegistry registry;

    public RoutingConfiguration(MeterRegistry registry) {
        this.registry = registry;
    }

    @Override
    public void addCorsMappings(CorsRegistry corsRegistry) {
        corsRegistry.addMapping(API_URL + "/**").allowedMethods("GET", "POST");
    }

    @Bean
    public RouterFunction<?> indexRouter(final IndexHandler indexHandler, final ErrorHandler errorHandler) {
        RouterFunctionMetrics metrics = new RouterFunctionMetrics(this.registry);
        return route(GET("/"), indexHandler::getRestApiDocs).filter(metrics.timer("http.request.index.page"));      
    }

    @Bean
    public RouterFunction<?> bookRouter(final BookHandler handler, final ErrorHandler errorHandler) {
        return 
                nest(path(API_URL + "/v1/book"), 
                    nest(accept(MediaType.APPLICATION_JSON), 
                        route(GET("/"), handler::getAllBooks)
                        .andRoute(POST("/"), handler::saveBook)
                    ).andOther(route(RequestPredicates.all(), errorHandler::notFound))
                );
    }
}