Currently, there is no setting available to allow you to indicate within Importacular that you would like the column for Constituent ID to be included in your Raiser's Edge Gift Batch. If your organisation's policy is to include the Constituent ID as a column in Batch entry, then you will need to manually add this column to your Batch once it has been created by Importacular.
Once you have added the field, it will auto-populate with the Constituent IDs for each Constituent within the Batch.