Ensure that the SMS gateway is properly connected to a reliable power source and is powered on. A stable power supply is essential for uninterrupted operation.

Confirm that the network (Ethernet) cable is securely connected to the gateway. Then, verify if the device is reachable via its assigned IP address to ensure proper network communication.

Make sure the SIM card inserted in the SMS gateway has sufficient credit or an active data plan to enable the sending of reply messages for code requests.

Verify that the connection between the application server and the SMS gateway is active and stable, and confirm that bidirectional communication is functioning correctly.

If the issue persists, contact support@acsys.com