Hard to tell exactly why that might happen. From your Spoke screenshot, I can see that you have a directional light in the scene-- that makes it hard to tell if the lightmap is working. Can you delete it and still see shadows on your mesh? If not, your lightmap is not showing up.

Second, could you take a screenshot of your Blender material graph? That will help me see if it's set up correctly. Bear in mind that using lightmaps is designed to work with the 'unlit' material type, not a Principled BSDF material. If you're using the latter, you may find you need to turn up the lightmap intensity quite a bit to overcome the effect of your realtime lighting/cubemap reflections.

I confirm the lightmap is working in Spoke , as you can see with the screen attached (without directional light) . I followed each step with the tutorial posted by Mozilla Hubs on Youtube (FULL VIDEO: Hubs How-to: Using the Hubs Blender Exporter & light mapping) , before I export the gltf file I checked shading set up and everything is Ok (screencut : shading1) , then I delete the BSDF and replaced by background , then export the gltf . So strange everything is fine in Spoke , but only the lightmap is disappear in the room scene.