yarn start

yarn add node-sass@^5.0.0 yarn add react-router-dom and yarn add @types/react-router-dom

To manager Firebase host: npm install -g firebase-tools

Firebase roles: { "rules": { "rooms":{ ".read": false, ".write": "auth != null", "$roomId":{ ".read": true, ".write": "auth != null && (!data.exists()||data.parent().child('authorId').val() == auth.id)", "questions": { ".read": true, ".write": "auth !=null && (!data.exists()||data.parent().child('authorId').val() == auth.id)", "likes": { ".read": true, ".write":"auth !=null && (!data.exists()||data.parent().child('authorId').val() == auth.id)" } } } } } }