RAK3272-S connection to private gateway

I have a gateway module based on sx1302 which is on the band of EU868. I am trying to connect my RAK3272 modules to the gateway via following LoRaWan_Class_B example. I have changed the OTAA_DEVUI and OTAA_APPEUI with the concentrator EUI. What might I have missing?

Thank you in advence.

Why would you change the DevEUI and AppEUI to the concentrators EUI? That makes no sense at all.

Do you have you concentrator connected to a LoRaWAN server?
You have to setup an application on the LoRaWAN server and register the device there with it’s own DevEUI/AppEUI and AppKey. They came pre-flashed with the device. But you can use any other EUI/Key combination of course.
You have to choose in the LoRaWAN server the EU868 region as well.

Did you setup the RAK3172 to EU868 band?

*Yes I setup the RAK3172 to EU868 Band.
*No I did not setup the LoRaWAN Server. I thought that I can do it through the concentrater without needing to an Server. I am using packet forwarder script and it’s forwarding packets to the localhost. If it’s not too much to ask, is there a way that I can do without public LoRaWan Server like TTN. I would like to use concentrator as server.
Thank you in advence

As far as I know there is no way to use LoRaWAN devices without a server.