Thanks again Jim! This didn't work unfortunately. I believe that the "options" field somehow needs to represent that "Keep the original issue and tie its resolution to this project" is checked as it would be when converting the issue manually in Workfront. I've asked Workfront support for assistance with this, I'll see what they come back. For anyone's future reference -
I found the below in the HTML of the page, and I think this needs to be in the "options".
I have tried the below in the "options" field but I keep getting an "unknown copy option" error. checkable_preserveIssue: "checked" checkable_preserveIssue: checked preserveIssue: checked preserveIssue: true "preserveIssue": "true" {"preserveIssue": "true"} {"checkable_preserveIssue": "true"} {checkable_preserveIssue: true} {preserveIssue: true} Yvonne Miaoulis Sage