How to deploy map offline? (cannot understand the term "frontend server directory")

[caixd-220529]

Thanks for the wonderful work!
In here, it mentions that:

Now you can point all occurrences to metis.lti.cs.cmu.edu:8085 in the frontend server directory to your own geocoding server.

I am wonder what is “frontend server directory”? How can I reach it?

I also want to know how to bind the map application to a specified port, e.g., 3000.

@shuyanzhou @frankxu2004 @neubig