react-admin: Unable to install from fork

I forked the project in order to add support for uploading audio files (it’s entirely necessary for my application) and after installing from npm (after adding "admin-on-rest": "popaulina/admin-on-rest" to my package.json), the package is in my node_modules folder but is missing its lib folder. I found a similar issue on another repo here. Does anyone know a work-around/can this be patched/am I doing something wrong?

I was able to get this to run locally by running babel -d ./lib ./src but this produces an error if added to a postinstall script.