Socket don't match when deploy

[Muhamedou Fi]

Hey i deploy the app on app.netlify.com
but when the deployement success socket don't match
this is my package.json
it open app normally when other user joined don't attach videos

{"name": "video",
  "version": "0.1.0",
  "private": true,

  "dependencies": {
    "@material-ui/core": "^4.9.7",
    "@material-ui/icons": "^4.9.1",
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.3.2",
    "@testing-library/user-event": "^7.1.2",
    "antd": "^4.1.4",
    "bootstrap": "^4.4.1",
    "concurrently": "^5.1.0",
    "cors": "^2.8.5",
    "express": "^4.17.1",
    "faker": "^4.1.0",
    "nodemon": "^2.0.2",
    "react": "^16.13.1",
    "react-bootstrap": "^1.0.0",
    "react-css-grid": "^2.0.0-0",
    "react-dom": "^16.13.1",
    "react-flexbox-grid": "^2.1.2",
    "react-grid-layout": "^0.18.3",
    "react-grid-system": "^6.3.0",
    "react-router": "^5.1.2",
    "react-router-dom": "^5.1.2",
    "react-scripts": "3.4.1",
    "reactstrap": "^8.4.1",
    "serve": "^14.0.1",
    "socket.io": "^2.3.0",
    "socket.io-client": "^2.3.0",
    "standard": "^14.3.3",
    "xss": "^1.0.8"
  },
  "scripts": {
    "dev": "concurrently -n 'server,client' -c 'red,green'  \"nodemon app.js\" \"SET NODE_ENV=dev react-scripts start\"",
    "start": "react-scripts start",
    "server": "SET NODE_ENV=production nodemon app.js & react-scripts start",
    "build": "react-scripts build",
    "heroku-postbuild": "npm run build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }}

and this is my configuration netlify netlify.toml

[build]
  command = "npm run build"
  publish = "/build"
  base ="/"

[[redirects]]
  from = "/*"
  to = "/index.html"
  status = 200