Not sure if this is right place, but really stumbled upon- no any info on google:
JIRA Service Desk 3.4.
curl -D- -u user:pass -X POST --data “{"fields":{"project":{"key":"TECH"},"parent":{"key":"TECH-456"},"summary":"Test ChargenNr","description":"some description","issuetype":{"name":"Sub-Task"}}}” -H “Content-Type:application/json” https://compnay.com/rest/api/2/issue/
i’m getting:customfield_10107":"Client Account is required