How to add command line switches to Dashboard?

I’m testing HA 0.118.3 in a Docker container in a Lubuntu VM. I’m migrating my config from a much older release (0.65.0), by copying across elements of my configuration.yaml file one section at a time.
I’ve copied my switch: section across, and the server restarted fine, but I can’t work out how to add my switches to the default dashboard. Can anyone advise on how to do this? I’ve tried adding various types of card, but the setup screens don’t list any of my switches in the entity dropdowns.
Here’s an example of my switch definitions in configuration.yaml:

  - platform: command_line
        command_on: 'curl -X GET "http://mydomain:nnnn/code/HumaxPower"'
        command_on: 'curl -X POST'
        command_off: '/usr/bin/curl -X POST'

Edit: I’ve also just noticed that none of my switches are listed in the States page, even though the HA log doesn’t indicate any errors loading my configuration.yaml.
Any ideas what I’ve done wrong here?

My guess is you have duplicate ‘switch’ sections. I highly doubt these are your only 2 switches in your whole config.

Move the platform: command_line to the same section as your other switches.

HA will take the first one it sees and ignore all duplicates.