How to configure mopidy to work with a USB Codec?

Q&A
1

I am trying to get mopidy to ouput to a Behringer UCA-222 but I can’t
get it to work at all.

What should I be doing to try and work out what is needed?

Running ‘aplay -l’ produces:-

**** List of PLAYBACK Hardware Devices ****
card 0: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones
[bcm2835 Headphones]
  Subdevices: 7/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice ✔ : subdevice ✔
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 1: CODEC [USB Audio CODEC], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM
i2s-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM
i2s-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Presumably the Behringer is “card 1: CODEC [USB Audio CODEC], device
0: USB Audio [USB Audio]”, how do I get mopidy to output to that?