我找到了这个。
我创建了这个ExchangeFilter函数：

private ExchangeFilterFunction myExchangeFilterFunction(OAuth2AuthorizedClientService clientService) {
    return new ExchangeFilterFunction() {
        @Override
        public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {
            Authentication authentication = SecurityContextHolder.getContext().getAuthentication();

            OAuth2AuthenticationToken oauthToken = (OAuth2AuthenticationToken) authentication;

            OAuth2AuthorizedClient client = clientService.loadAuthorizedClient(
                    oauthToken.getAuthorizedClientRegistrationId(),
                    oauthToken.getName());

            String accessToken = client.getAccessToken().getTokenValue();

            ClientRequest newRequest = ClientRequest.from(request)
                    .headers((headers) -> headers.setBearerAuth(accessToken))
                    .build();

            return next.exchange(newRequest);
        }
    };
}