封装业务流程的输入参数是附件时，如何传参？

可以用 base64 传参

出错返回：{'status': 1, 'data': {'sourceId': '643f69617486b0331e216b74', 'msg': 'Cannot invoke "com.mingdao.workflow.instance.domain.Work.getAppType()" because "work" is null', 'instanceId': '643f69617486b0331e216b73'}, 'msg': '成功'}

import  requests

posturl ="https://xxx.xxxx.com/api/workflow/hooks/NjQzZjYxZTY3NDg2YjAzMzFlMjE2NDU1/carqueery"
import base64

with open('C:/Users/Administrator/Desktop/yewu/1_信息采集使用授权及声明.pdf', 'rb') as f:
    pdf_bytes = f.read()  # read the PDF file in binary mode
    pdf_base64 = base64.b64encode(pdf_bytes).decode()  # convert the binary data to base64 string
data= {
        'appKey':'f7c1xxx5a676aa090',
        'sign':'ZDNhZxxxxxxxxxxxMyYWQ0ODBjZGYwNjIzYThlZDQyMDVlOGNiYWUwNTEyNGZiYTEyYQ==',
        'username':'xx',
        'authfile':pdf_base64,
        'usercertNo':'xxxxxxxxxx'
        }

re=requests.post(posturl,json = data)