I am trying to export an object (above right), and I put 3D text (not a texture) on it. But every time I export the glTF, the text does not come with it. Is there a way to get text, or is text not possible with the glTF format? In the image above, you can see the imported building on the left does not have the text, but I need the text to export.
glTF is a GPU-ready format that only supports meshes, not other types of geometry directly. To make the text compatible with glTF, look for the convert option in the Object menu of the 3D view:
Object -> Convert To... -> Mesh from Curve/Meta/Surf/Text
If needed, make a copy of the text beforehand. Once converted to a mesh, you won't be able to change the font or letters used, but you can apply normal mesh modifications to it.