Hello pkb81,
You can see the video about authentise here: https://www.youtube.com/watch?v=FG7BjTmIg-8
As you can see, the models are automatically placed to the platform. If you have any problems with 3D printing, you can always write to our support team at info@cgtrader.com - I'm sure they will help. :)
Also, it is important that the printer would be compatible - you can see more info here:
https://authentise.zendesk.com/hc/en-us/articles/202133338-What-are-the-compatible-printers-
Sorry for late reply. Hope this helps.
All the best,
Eduardas