Making Attachments Available in External Omniscripts (Managed Package)

For the managed package runtime, to render attachments on an external Omniscript:

Managed Package app icon This information is for Omnistudio for Managed Packages. For Omnistudio on standard runtime, see Omnistudio Help.

Go to your attachment, and download it.
Go to the Documents tab, and click New.
Check the box labeled Externally Available Image and upload the attachment as a document.
Right-click the image on the document, and select Copy Image Location.
Paste the image location in a simple text editor or notepad. Remove the host information and remove extraneous parameters so that the path resembles the format of this example: /servlet/servlet.ImageServer?id=015f4000002W0eV&oid=00Df400000380sD.
Navigate to the Record page where the file will be attached. If this is a Product record, edit the record layout to include the Product Attachment List Visualforce page.
Click the New Attachment button, and fill out the form.
Instead of uploading the file again, copy the modified URL from step 5, and paste it into the URL field..
Leave URL Name blank.
Set Content Type to Image.
Set Is Default Image to Yes, and Save the attachment.
The name is the record Id, which can be used to edit the record in the future.
The image is now accessible in external Omniscripts.