How to modify web app client using Docker ?

I am using the docker image: traccar/traccar:latest to run traccar on my server.

I want to make modifications on the web app, so I am trying to modify the files on /opt/traccar/web/
but they never really take effect, even after I restart or recreate the container.
the sources in chrome dev indicate that the files were unaffected.

how can I edit the source files of web folder and recompile it while using the docker image? is that even possible?

Have you set the key web.path on the Traccar configuration file? The standard one is this: <entry key='web.path'>./web</entry>. So you have to set the path to your own version. However since you are using docker, you'll have to create a volume to make it work and be available from inside the container. I never really tried but I guess this is going to work.