I've been trying to create custom starting values for the project issue keys using the External System Import to upload a CSV file that has only the following data:
Column A, Row 1: Issue Key
Column A, Row 2: ECO-13999
Column B, Row 1: Summary
Column B, Row 2: Test
However, when I try to map the fields upon upload, Issue Key or Project Issue Key or any similar system field isn't available. Did Jira remove this feature? How else would I be able to start the first item as ECO-14000?