From https://concaveearth.net forums ! Sign up today!
https://youtu.be/8Qj6CYXq1Wo
Requirements
Download and install Blender https://www.blender.org/download/
Download the model from this website or the link below (after registration) https://concaveearth.net/t/free-simple-concave-earth-3d-model-in-blender-includes-a-rotating-celestial-sphere-inside-of-a-transparent-hollow-concave-earth/34
Unzip the contents to your desired location
Open the CONCAVEEARTH.net Basic Concave Earth Example.blend file and wait for Blender to open and the project to load.
Click Viewport Shading to view the model
Enjoy!