Trying to connect external device for testing but unable to connect

Hi

I am new to appium and trying to use the external device for testing my app,but unable to connect it.

Getting an following error

WebDriverException: Message: A new session could not be created. (Original error: Unable to install [/var/folders/_h/bbj17n0x4pn03hqywrp_pbbh0000gp/T/11525-52401-1gyeape/submodules/SafariLauncher/build/Release-iphoneos/SafariLauncher.app] to device with id [6b5add36c3e2b6b8fef7b8b85829dd4b5609b931]. Error [Error: Command failed: ])

But script can be tested in an simulator

Can anyone help me??

Thanks
Abinesh