How can I app 3D text with Ruby?

How can I app 3D text with Ruby?
The question is, I will add instance_name of the object I chose to display on the face?
How should Ruby be written?

I don’t understand what you wrote, but the process to add 3DText via the Ruby API is:

  • #add_3d_text to the appropriate Entities collection (it will be placed at the origin of that Entities)
  • use a Transformation to locate the text at the required location

All of this what Steve say can not be done in SketchUp for Schools and on that operating system and graphic card you stated in your forum profile.
Please correct it!
You need to use SketchUp desktop version on Windows or Mac operating system. Graphic card is depends on your computer hardware.

The task you described is not clear to me either.

I hadn’t looked at your profile. @dezmo is correct: SketchUp for Schools does not support the Ruby API.