Use custom field/variable for the To: email address in an Ad Hoc notification

Hi,

New to the Solarwinds ticketing system, but we are trying to build a process in one of our services that relies on some information from third party vendors. As part of this process, we would like the requestor to fill out a field such as "Email Address" and be able to use that custom field for "Email Address" when a notification is sent later on in the process. However, when trying to use {{Email Address}} as a variable in the process To or CC fields, we get an error that it is an "Invalid Email" as in the attached image.

Is there a different/better way to handle this?

Thanks for the help in advance.