How to setup the context?

I've just launch the api server jar in port localhost:8080/dtrack, and I would like to deploy the frontend in a context different than root.
When I use the Apache with frontend files in root context and API_SERVER_URL=http://localhost:8080/dtrack all works nice.

But when I move the frontend files to another context it doesn't works. Frontend seems to expect files on root context.
Is there any variable I could change to point to the new context?

Start with the frontend files and the API_SERVER_URL configuration while reproducing the deployment behind Apache at /dtrack and another non-root context. Trace which frontend URLs still assume the root context; done means the frontend assets and API requests work from the alternate context without changing the root-context setup.

Written by the indexing model from the issue text.