I printed clicked the link for the Batch API call URL variable and it says the following: 'Production tokens cannot be used in the sandbox environment. Please use https://cloud.iexapis.com'
On second thought, It seems I wasn't using the sandbox secrets IEX Token provided by the tutorial in the first half of the tutorial. That might have screwed things up for the second half.
I printed clicked the link for the Batch API call URL variable and it says the following: 'Production tokens cannot be used in the sandbox environment. Please use https://cloud.iexapis.com'