ZBT-1 can't be configured for Thread

I bought a second ZBT-1 to make a Thread network. Plugged it in, selected “Thread” when configuring it, got a message saying it failed.

Now I can’t even try to configure it as it doesn’t show up anywhere in Home Assistant. Taking it out and plugging it in again doesn’t make a “New device” notification show up.

What am I supposed to do ?

Goto UI->System->Hardware->All Hardware.
Do you see anything that looks like:
/dev/serial/by-id/usb-Nabu_Casa_SkyConnect_v1.0_blah-blah-if00-port0 ?

If yes, then configure your OTBR AddOn to use this.
If no, then SSH into HA, and unplug, then plug in the ZBT-1 then enter dmesg and see what is going on at the very end of the dmesg output.

I tried restarting the pi HA is hosted on and I got the new device notification. Now when I click Configure → Thread I get this :

I don’t know what you mean by “OTBR”. I thought this was supposed to be plug-and-play ?