docs: @Override
      public void filter(ClientRequestContext requestContext) {
          //
          if (requestContext == null || jwt == null || requestContext.getHeaders().containsKey("Authorization")) {
              return;
          }
          if (header == null || header.equals("")) {
              header = "Authorization";
          }
          final String headerValue;
          if ("Authorization".equals(header)) {
              headerValue = "Bearer " + jwt;
          } else {
              headerValue = jwt;
          }
  
          requestContext.getHeaders().add(header, headerValue);
      }