Update an open source React app and deploy it to my server

There is an open source React app that hasn't been updated for 2 years that I would like to use. There are instructions on the Gitlab repo on how to compile it, but attempting to do so using yarn throws up a bunch of errors.

There is an instance of the app hosted at manuscripts.io, but that is an older version to what is on the repo: https://gitlab.com/mpapp-public/manuscripts-frontend which I can't seem to build