12306 列车信息获取失败？

import requestscookies = {    '_jc_save_fromDate': '2021-05-01',    #开车的时间}headers = {    'Connection': 'keep-alive',    'Cache-Control': 'no-cache',    'sec-ch-ua': '^\^',    'Accept': '*/*',    'X-Requested-With': 'XMLHttpRequest',    'If-Modified-Since': '0',    'sec-ch-ua-mobile': '?0',    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.85 Safari/537.36',    'Sec-Fetch-Site': 'same-origin',    'Sec-Fetch-Mode': 'cors',    'Sec-Fetch-Dest': 'empty',    'Referer': 'https://kyfw.12306.cn/otn/leftTicket/init?linktypeid=dc',    'Accept-Language': 'zh-CN,zh;q=0.9',}params = (    ('leftTicketDTO.train_date', '2021-05-01'),    ('leftTicketDTO.from_station', 'SHH'),    ('leftTicketDTO.to_station', 'BJP'),    ('purpose_codes', 'ADULT'),)response = requests.get('https://kyfw.12306.cn/otn/leftTicket/query', headers=headers, params=params,cookies=cookies)print(response.json())