Hi Paulo,
I've dug into this a bit, and came across an older communities post related to adding Catalog attachments to Service Desk Manager, at the following link:
How to view service catalog attachments in service desk
The solution contained in the above link requires an instance of PAM, in which you can create a workflow that will download the SC attachment and upload it to SDM. Please take a look, and feel free to reach out with any questions you come across!
-Eddie