Hello,
The second column containing the ID is not displayed in the Columns tab. If you want to return the Lookup ID, you just have to select the Lookup column. The associated ID will be automatically added to the results in a second column.
For your information, if you need to filter the data according to the Lookup ID, you have to set the LookupId to true inside the condition.

Don't hesitate to contact us if you need more information.
Regards,
Marien Monnier