Answer
Aurena doesn't support the Clickable Hyperlink custom-field attribute the way IEE does — there's no equivalent setting that makes a custom field itself render as a native clickable link in Aurena. The supported workaround is to add a Custom Command to the page instead, configured to open the relevant URL (which can be built dynamically from the field's value) — this gives equivalent click-to-open-URL behavior, just via a command rather than through the field's own display styling.