Update Story point for Subtask using python Jira API

Hi all,
I used lib JIRA of Python to create subtask.
My payload is
payload = {
“project”:{“id”:‘10032’},
“summary”: “ciel summary”,
“issuetype”: {“id”:‘10003’},
“parent”: {‘id’: ‘21384’}
}
iss = jira.create_issue(fields=payload)
issue_update = jira.issue(iss)

issue_update.update(field={“customfield_10014”:3})

but it’s not work.
customfield_10014 is storypoint I needed to set.

Pls help me resolve this problem.
Thank.