Use specific marketplace designs in my Spreadshop

There are some designs on the marketplace that I want to use in my Spreadshop, but I have a hard time finding them in the designer when I want to create products. Is there a way to find these designs in the designer by user ID of the creator or by design ID?

I would love to use designs from this account: https://www.spreadshirt.nl/user/Tekenaartje in this shop: https://www.tekenaartje.nl/t-shirt-shop#!/