Hi Ayumix01,
the add-on is still in development and some features could be missing or in progress (or simply done manually).
:-)
Anyway, the blender lights aren't exported yet in the a-frame project: the add-on automatically adds two ligths in your final scene: a directional one and an ambient one.
So you have two possibilities:
1) Try to export your scene with "Cast shadows" OFF and see if the textures are ok
2) Try to export your scene with "Cast shadows" ON, and try to change the light's settings. Inside your web browser with your scene loaded, pressi CONTROL + ALT + i -> to show the main a-frame inspector. Go at the end of the scene tree (see the attachment) and try to change the light's intensity.
If you want, you can share your blender file, if the problem still persists. I'll check out it.
Hope it helps.
Regards
Slade
