Open the Subtask: Navigate to the corresponding subtask that need to convert into a subtask. We can locate it by accessing the parent task or through the issue search.
Open the More Options Menu: On the subtask’s page, locate the “More Options” button represented by three dots (…). Click on it to reveal a dropdown menu.

Select “Move”: From the dropdown menu, choose the “Move” option. This action will open the Move Issue page.

Select “Issue Type: Task”: On the Move Issue page, you’ll see the “Issue Type” field. Select “Task” from the available options to convert the subtask into a task.
Update Task Details: Review and update the necessary details for the task, such as the summary, assignee, priority, due date, and any other relevant fields.
Save the Changes: Once you have made the required updates, click on the “Move” or “Save” button to convert the subtask into a standalone task.
After saving the changes, the subtask will be converted into a regular task in Jira Software. It will have its own unique issue key and can be managed independently from its former parent task.