Looks like the OP is on SketchUp Shop? So no extension options for text in model. Another serious limitation of 3D text is that it’s not editable. 3D text works great for what it is, but it’s not efficient to label a whole con doc with it. Best option for the OP might be outputting the model to 2D and labeling with an image editor after.
Take a look at this thread about kludging condocs in the SketchUp Free, where I use some basic 3D text to label a model.