Download Diagnostic Log - Transaction Console - Privilege Missing

We have a custom role that allows access to the Transaction Console, but we are unable to download the diagnostic log, we receive an 'Access Denied' error. We would like to know which specific privilege needs to be added to enable downloading the diagnostic log. Due to internal restrictions, we cannot assign a full role, so we need to identify the exact privilege required.

https://url/businessProcessConsoleTransactionDetails/action/fetchDiagnosticLog

{title: "Bad Request", status: "400", o:errorDetails: [{detail: "Access Denied"}]}

1. o:errorDetails: [{detail: "Access Denied"}] 0: {detail: "Access Denied"} status: "400" title: "Bad Request"