Turn items into sub-tasks

Open the checklist's ••• menu.
Select Convert unchecked to subtask.

Every unchecked item becomes a sub-task of the current issue: the item's text becomes the sub-task summary and its details become the description. Each converted item is marked Done and gets - Converted to a subtask KEY.

The project needs a sub-task issue type, and the current issue can't itself be a sub-task. If nothing can be converted, Jira shows Conversion failed — check that sub-tasks are enabled for the project.