Hi @gabrielpc1190, the “Attachment Field Name” field would expect just the name of the binary property (or if there are multiple attachments, a comma separated list of these names).
$binary would, however, reference the entire dataset. So you probably want to use an expression like {{ Object.keys($binary).join(',') }} instead? The Object.keys method would read the names, .join(‘,’) would return these as a comma separated string.
This seems to work fine for me:
