Reading Masks made by a different software

Hello,

I can import open access data, human heart segmentation. I can simply open and see the segmentation, but it is like images, I cannot work on it.
What I need is just 3D export of that segmentation, STL format. The goal is to print the model by a 3D printer.
Kindly find the data on;
https://zmiclab.github.io/zxh/0/mmwhs/

Thank you for your help in advance.

Sincerely,
Arezoo,