Hello AJ,
We do not have a predefined Property which stores the value of the "Updates configuration file URL" field.
In order to store the the value of the "Updates configuration file URL" field, you can go to
Install parameters page from the "Package Definition" group, create a new Property with the name (e.g. MYPROP) and the value set to the download URL you want and then go back to
Updater page from the "Product Information" group, tick the "Check for updates before installation (requires EXE setup file)", and in the "Updates configuration file URL" field add your property e.g.
MYPROP
If you have any further questions or doubts, don't hesitate to contact us.
Regards,
Catalin