Azure ARM Template Troubleshooting & Fix

So I have this ARM template to deploy websites built in ReactJS: https://hator.blob.core.windows.net/coolcloud/template5.json It successfully creates a new resource and deploys a website in Azure, however if the reactjs websites have third party libraries installed then it does not work which makes me think I am missing "startupCommand" like "npm install && npm start" however when trying it implement it I did not get a successful result. Check it out in your side and if you are able to fix it let me know so I can make a payment.