Q: how can I configure sound if "Headphones" appears when I push volume   or -

Hello rafgarciafrommex,

Thanks for using Apple Support Communities.

I see from your post that you're unable to change the volume of your iPhone and there's no audio coming from the speaker.  To troubleshoot this issue I suggest going through the steps in the link below.

If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support

Cheers.