AuthenticationProvider is not called

[j1cs]

i have the following code:
https://github.com/j1cs/oauth-mapper-error/blob/master/maintainer/src/main/java/me/jics/KeycloakAuthenticationProvider.java#L25

public class KeycloakAuthenticationProvider implements AuthenticationProvider {

    private final KeycloakClient client;

    @Override
    public Publisher<AuthenticationResponse> authenticate(HttpRequest<?> httpRequest, AuthenticationRequest<?, ?> authenticationRequest) {
        return Mono.from(client.getClaims(httpRequest.getHeaders().get("Authorization")))
                .map(requestPartyToken ->
                        {
                            log.info(requestPartyToken.toString()); // ain't entering.
                            return AuthenticationResponse.success(requestPartyToken.getAccess().getPreferredUsername(),
                                    requestPartyToken.getAccess().getRealmAccess().getRoles());
                        }
                );
    }
}

But doesn't seems is called. Even sending the Authorization header in the request to the controller.
I created an example to debug it. https://github.com/j1cs/oauth-mapper-error
https://raw.githubusercontent.com/j1cs/oauth-mapper-error/master/log.txt