Why I can't post a Sketchfab model as reply in groups forum?

Why I can’t post a Sketchfab model as reply in groups forum?

Plane1 by adriansnetlis on Sketchfab

Anyway, I can post it here… Maybe you should solve that in Groups forums?

The community groups have a more simplified posting structure than in the forum proper. However, did you try using the sketchfab BBcode? I suspect that may work even though there’s not a Sketchfab button in the posting interface.

Well… It shows so Sketchfab BB code isn’t allowed. The developers of site might fix it so it is allowed as I want to preview my models…