Unfortunately, to use the iSmartgate with Amazon Alexa, you require an internet connection. Hence, you cannot use the iSmartgate with Amazon Alexa without Wi-Fi. With that said, you can configure your iSmartgate device using Access Point mode. You would have to opt for this mode during the initial set up of your device.
Furthermore, the device cannot switch from Wi-Fi to Access Point mode automatically. Keep in mind that while using this mode, you do not have remote access, access to users, or the ability to use third-party apps like Amazon Alexa. You would have to connect to the iSmartgate’s Wi-Fi network in order to open or close the gate.