In case of an option 1 multisite, do I need to create 3 sites? Then I would need to create and add a product for each site, right? And finally I add all to the Scope information?

Yes, this is correct. In this example, all 3 sites have to be created, and products for each site shall be created and added to the respective site.

During the preparation of the audit work order, all products have to be added to the certification scope.

Please note that, depending on whether the Option 1 multisite producer is operating a QMS or not, the applicable certification option shall be selected (Option 1 multisite with or without QMS).