How to set this SLZB-06 up as a repeater?

Hello,

I also want to integrate an SLZB-06 as a Zigbee router in my Z2m. How exactly do I do this? I have HomeAssistant running as Docker in Synology.

Here are my settings. How can I add this router to my existing Zigbee network?
Normal paring as with the devices does not work.

And this two pictures from my config.

Same here too. It actually shows up in the Zigbee network, but as a different network so not joined. Wondering if a firmware bug for joining?

Did someone figure this out ?

Iā€™m about to jump into this rabbit hole. Are the folks above saying that the solution in post #2 from about 6 months ago is no longer working? Firmware bug?