Thingy91x ZigBee Implementation

I need to understand the basics of creating a ZigBee application from the examples provided for both the Thingy91 (nrf52840) and the Thingy91x (nrf5340).
As I understand it, both devices support ZigBee and the "Shell" example builds for each respective development kit, but I do not understand the steps to migrate the examples to each of the Thingy91 devices.

I have seen the question at:
Zigbee coordinator on the thingy91_nrf52840 - Nordic Q&A - Nordic DevZone - Nordic DevZone

And I raised a question there, but I would like to understand the procedure to get this working - in the event that I have custom boards.

1. Create new application -> Copy from Sample

2. Select the "ZigBee Network Coordinator" sample

3. Add build configuration. Select Board Target -> Nordic Kits -> thingy91/nrf52840 || thingy91x/nrf5340 ns

4. Click Build Configuration Button -> expect failure

5. Create a new Device Tree Overlay and paste the text:

/ {
chosen {
ncs,zigbee-timer = &timer2;
zephyr,ieee802154 = &ieee802154;
};
};

&timer2 {
status = "okay";
};

&ieee802154 {
status = "okay";
};

6. Go to Actions -> Build and rebuild.

Can you please explain the step I am missing, as this build fails