There is a Chinese problem in the JSON request body data when Python requests

Example , When creating a wechat official account custom menu , Program ：

# Create applet menu
def create_public_menu():
# obtain token
token = get_access_token()
# json Request data
payload = {
"button": [
{
"type": "miniprogram",
"name": " Applet ",
"url": "https://mp.weixin.qq.com",
"appid": "appid",
"pagepath": "pages/index/index"
}
]
}
res = requests.post('https://api.weixin.qq.com/cgi-bin/menu/create?access_token=%s' % (token,), json=payload)
print(json.dumps(res.json(), ensure_ascii=False, indent=2))
pass

The wechat public platform system returned an error ：

{
"errcode": 40033,
"errmsg": "invalid charset. please check your request, if include \\uxxxx will create fail! ri