how to properly create a rest method using dto

Question

I need to send a request to a third-party service, then get an object from the response and display it on the browser.

package com.statusinfonew.springboot.controller;

import java.util.Collections;
import java.util.List;
import lombok.Data;
import lombok.val;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import com.statusinfonew.springboot.model.ParamsPays;
import com.statusinfonew.springboot.service.dto.OpenJsonFormat;

@Controller
@RestController
public class MyRestController {
    
    RestTemplate restTemlate;
    
    
    @GetMapping({"/"})
    public String showGeneralPage(Model model) {
                    model.addAttribute("general", "Welcome to App");
                return "hello";
        
    }

      @GetMapping(path = "/go")
      public List<ParamsPays> getInfoError(@RequestParam(value="token") String token, 
                             @RequestParam(value="orderId")String orderId){
        final String url =String.format("https://exemple.ru/payment/rest/getOrderStatus.do? 
        token=%s&orderId=%s", token, orderId);
                     OpenJsonFormat dto =restTemlate.getForObject(url, OpenJsonFormat.class);       
                     return Collections.singletonList(toModel(dto));
    }
            
    private ParamsPays toModel(OpenJsonFormat dto) {
      return new ParamsPays();
    }

package com.statusinfonew.springboot.service.dto;

import java.util.Date;

import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonProperty;

import lombok.Data;
        
    @Data
    public class OpenJsonFormat {
     @JsonProperty("actionCode")
     private String actionCode;
     @JsonProperty("amount")
     private String amount;
     @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
     private Date date;
    }
    

When I enter a get request, an error is issued:

This application has no explicit mapping for /error, so you are seeing this as a fallback.

http://localhost:8080/go?token=sdwggvpa0k4ponpkt9&orderId=6afsf0-a0bc-7ffd-a9a8-790d4s179

Wed Apr 21 21:26:35 SAMT 2021 There was an unexpected error (type=Internal Server Error, status=500).

I understand that I am making a gross mistake. Please help me figure it out