class Authentication: Fragment(){

private lateinit var mCallbacks: PhoneAuthProvider.OnVerificationStateChangedCallbacks

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    return inflater.inflate(R.layout.auth,container,false)



}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    authBtn.setOnClickListener{
        progressBar.setVisibility(View.VISIBLE)
        edt_number.setEnabled(false)
        authBtn.setEnabled(false)

        val phone = edt_number.text.toString()

        PhoneAuthProvider.getInstance().verifyPhoneNumber(
                phone, // Phone number to verify
                60,             // Timeout duration
                TimeUnit.SECONDS,   // Unit of timeout
                activity!!,           // Activity (for callback binding)
                mCallbacks)
        mCallbacks = object : PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
            override fun onVerificationCompleted(p0: PhoneAuthCredential?) {

            }

            override fun onVerificationFailed(p0: FirebaseException?) { TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
            }
        }
    }
}

mCallbacks = object : PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
        override fun onVerificationCompleted(p0: PhoneAuthCredential?) {

        }
        override fun onVerificationFailed(p0: FirebaseException?) { TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
        }
    }
    PhoneAuthProvider.getInstance().verifyPhoneNumber(
            phone, // Phone number to verify
            60,             // Timeout duration
            TimeUnit.SECONDS,   // Unit of timeout
            activity!!,           // Activity (for callback binding)
            mCallbacks)