curl --location --request POST 'https://api.kfim.cn/complaint_gate/wechat_download_pic' \
--data-urlencode 'complaint_no=' \
--data-urlencode 'picture_url=' \
--data-urlencode 'business_code=' \
--data-urlencode 'mch_num=' \
--data-urlencode 'timestamp=' \
--data-urlencode 'sign='{
"code": 0,
"msg": "string",
"data": {
"picture": "string",
"picture_type": "string"
}
}