Advice on running local dev webserver

[Lewis John McGibbney]

Hi dev@,
I'm working on implementing a Apache Flagon UserALE JS analytics backend for 
Airflow cf. https://github.com/apache/airflow/pull/16230
Specifically, in this thread I'm asking how to run the webserver locally so I 
can debug it. Ideally this does not involve deploying into Docker or anything 
yet. I was expecting to be able to run yarn dev from 
https://github.com/apache/airflow/tree/main/airflow/www but that doesn't seem 
to be working.
Any ideas?
Thank you
lewismc