return jwt to thymeleaf fragment - spring-boot

Question

I use spring boot with thymeleaf, spring security and spring cloud gateway.
User enter login/password and get a token. I search a way to get this tokin and put it in a cookie or in a hidden field in fragment. Need to to do some ajax call from thymeleaf page.
#EnableWebFluxSecurity
#EnableReactiveMethodSecurity
public class WebFluxSecurityConfig {
#Autowired
private WebFluxAuthManager authManager;
#Autowired
private WebFluxSecurityContextRepository webFluxSecurityContextRepository;
#Bean
protected SecurityWebFilterChain securityFilterChange(ServerHttpSecurity http) throws Exception {
http.csrf().disable()
.securityContextRepository(webFluxSecurityContextRepository)
.authorizeExchange()
// URL that starts with / or /login/
.pathMatchers("/", "/login", "/js/**", "/img/**", "/css/**").permitAll()
.anyExchange().authenticated()
.and().formLogin().loginPage("/login")
.authenticationSuccessHandler(new RedirectServerAuthenticationSuccessHandler("/two")
).and().csrf().disable();
http.authenticationManager(authManager);
return http.build();
}
}
#Component
public class WebFluxSecurityContextRepository implements ServerSecurityContextRepository {
private final WebFluxAuthManager authManager;
public WebFluxSecurityContextRepository(WebFluxAuthManager authManager) {
this.authManager = authManager;
}
#Override
public Mono<Void> save(ServerWebExchange exchange, SecurityContext context) {
return Mono.empty();
}
#Override
public Mono<SecurityContext> load(ServerWebExchange exchange) {
ServerHttpRequest request = exchange.getRequest();
String authHeader = request.getHeaders().getFirst(HttpHeaders.AUTHORIZATION);
if (authHeader != null && authHeader.startsWith("Bearer ")) {
String authToken = authHeader.substring(7);
Authentication auth = new UsernamePasswordAuthenticationToken(authToken, authToken);
return this.authManager.authenticate(auth).map((authentication) -> {
return new SecurityContextImpl(authentication);
});
} else {
return Mono.empty();
}
}
}
#Component
public class WebFluxAuthManager implements ReactiveAuthenticationManager {
#Value("${gateway.url}")
private String gatewayUrl;
#Autowired
private WebClient webClient;
#Override
public Mono<Authentication> authenticate(Authentication authentication) {
Mono<ResponseEntity<String>> mResponse = webClient.post()
.uri("/auth/login")
.acceptCharset(Charset.forName("UTF-8"))
.body(Mono.just(loginRequest), LoginDto.class)
.retrieve()
.toEntity(String.class);
...
...
return Mono.just(new UsernamePasswordAuthenticationToken(username, password, authorities));
}