hello , i have problem about sending file to another iphone, i can,t find another iphone bluetooth , please help thanks

This has never been a feature of iPhone, iPad or iPod.

It will not transfer files via bluetooth.

Iphone supports bluetooth for handsfree telephone devices, stereo speakers/headsets, some keyboards, some apps from the app store and internet tethering if provided by your carrier.

Other than this, it will not connect to other phones or computers.

If you are referring to an iPhone 4, you would need AirDrop to send files but that requires an iPhone 5 or later > Share content with AirDrop from your iPhone, iPad, or iPod touch - Apple Support