Illumination in the background of the skewer cable

[fabota]

Please, I'm new to keyshot and I can't light the underside of the skewer handle

[DT]

The handles have reflections.  Can you clarify your issue?  Is the environment ground flat?

[fabota]

Yes it is flat, I will send the file

[RRIS]

Do you mean the flat surfaces facing the viewer? Completely flat surfaces like that are tricky, you have to rely on reflections 100% on metal object and the problem is the all reflect the same thing, since they're completely flat. You can carefully position a lighting pin in your environment with some falloff, to create a very suble gradient in your reflections, placement is super critical.
An easier solution would be to add some subtle dome geometry on the ends of the handles, it won't need much to create a huge difference (and some small fillets wouldn't hurt either on the edges).

[fabota]

Perfect, thanks for your tips, thank you

[DT]

Sorry for the late response.

I looked at your posted file and noticed the HDRI environments are pretty large, 16,000mm. 

If I understand your problem correctly, try making the HDRI environment smaller, 1200mm for more control.  See attached render, Adjusted HDR, and KSP file.