I am developing an MS Office addin in React JS. I want to change the base url of my app, by adding prefix to it. Now my default app run on "http://localhost:3000/taskpane.html", but I want to run it on "http://localhost:3000/plan/taskpane.html", as I have to run two app on same domain with different prefixes.
I have tried different solutions but none of them worked for me. I also tried "homepage" in package.json but still failed. Below is the default folder structure, create by yeoman-generator.
NOTE: It would be good if you provide a solution for both LOCALHOST and PRODUCTION.
My Package.json file is:



