private String getIMEINumber() {
        String IMEINumber = "";
        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED) {
            TelephonyManager telephonyMgr = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                IMEINumber = telephonyMgr.getImei(0);
            } else {
                IMEINumber = telephonyMgr.getDeviceId();
            }
        }
        return IMEINumber;
    }





public static String getUniqueIMEIId(Context context) {
        try {
            TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            if (ActivityCompat.checkSelfPermission(context, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
                // TODO: Consider calling
                //    ActivityCompat#requestPermissions
                // here to request the missing permissions, and then overriding
                //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                //                                          int[] grantResults)
                // to handle the case where the user grants the permission. See the documentation
                // for ActivityCompat#requestPermissions for more details.
                return "";
            }
            String imei = telephonyManager.getImei();
            Log.e("imei", "=" + imei);
            if (imei != null && !imei.isEmpty()) {
                return imei;
            } else {
                return android.os.Build.SERIAL;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "not_found";
    }