create-react-app-buildpack
                                
                                 create-react-app-buildpack copied to clipboard
                                
                                    create-react-app-buildpack copied to clipboard
                            
                            
                            
                        Add instructions for setting buildpack on an existing heroku app
I discovered this when configuring an existing react app already deployed to heroku, and thought it may be useful for others.
I used:
heroku buildpacks:remove heroku/nodejs
heroku buildpacks:add mars/create-react-app