Unable to create new config

Bug description

Hi! i am kinda new to jupyter, I am running into trouble creating a very basic test entry..

When trying to create a basic test setup following the installation:

c.ServerProxy.servers = {
    "test-server": {
        "command": ["echo", "Hello_World"]
    }
}

I get a launcher with the entry missing...

also trying to connect via https://myFQDN/hub/test-server i get no command or any kind of log about the entry.

i haven't been able to get past this.

How to reproduce

No idea how not to produce...

Expected behaviour

A launcher item to appear, when pressed printing Hello_World to the console of jupyterhub running

Actual behaviour

Nothing happening

Your personal set up

OS: Contaired setup: jupyterhub/jupyterhub:5
Version(s): jupyterhub: 5.2.0, Python: 3.10.12

Full environment

relevant packages: ``` jupyter-events @ file:///tmp/wheelhouse/jupyter_events-0.10.0-py3-none-any.whl jupyter-lsp==2.2.5 jupyter_client==8.6.3 jupyter_core==5.7.2 jupyter_server==2.14.2 jupyter_server_proxy==4.4.0 jupyter_server_terminals==0.5.3 jupyterhub @ file:///tmp/wheelhouse/jupyterhub-5.2.0-py3-none-any.whl jupyterlab==4.2.5 jupyterlab_pygments==0.3.0 jupyterlab_server==2.27.3 ```

Configuration

my jupyterhub_config.py is sensitive, i get the same error on dummy authentication and my now production OIDC auth so (in my opinion) irrelevant. ```python c.ServerProxy.servers = { "test-server": { "command": ["echo", "Hello_World"] } } ```

Logs

No relevant logs

jupyterhub / jupyter-server-proxy