The Open attachment preview function converts an attachment in Corteza to a reader.
Similar to the Open original attachment, the difference is preview is smaller in size (like thumbnail images)
So it is not possible to open/download a rendered template (e.g. PDF File) directly in the browser via workflow.
What works for me is opening the record page of the rendered template via the workflow task “Redirect user to the record page”.
But what is the purpose / use case of the function “Open original attachment”?
It converts an attachment to a Reader object, fine. But I’m not sure what I can do with the Reader afterwards?
A reader is used for reading data from a file inside workflows.
What you’re trying to do should be saving the file to a field and then redirecting the user to the record page/refreshing the blocks with the workflow prompt step.
Then the user has to click on the preview to “open it” and read it.