eslint not showing the error sign when it is supposed to

I am in react project and have typescriot in it.

I create react project with typescript by command

npx create-react-app my-app --template typescript

It working properly which mean i do npm start, it start the starting react page !!

I wanted to add a component and this is my component

import React, { useState } from "react";

interface Person {
  firstname: string;
  lastName: string;
}
interface Props {
  text: string;
  ok?: boolean;
  i?: number;
  fn: (bob: string) => number;
  obj: Person;
}

export const TextField: React.FC<Props> = () => {
  const [count, setCount] = useState<number | null>(5);
  setCount(undefined);
  return (
    <div>
      <input />
    </div>
  );
};

my problem with this code:

Why is my eslint not showing any error or warning !!

this is my package.json:

{
  "name": "shadow-casting",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.16.5",
    "@testing-library/react": "^13.4.0",
    "@testing-library/user-event": "^13.5.0",
    "@types/jest": "^27.5.2",
    "@types/node": "^16.11.59",
    "@types/react": "^18.0.20",
    "@types/react-dom": "^18.0.6",
    "react": "^18.2.0",
    "react-dom": "^18.2.0",
    "react-scripts": "5.0.1",
    "typescript": "^4.8.3",
    "web-vitals": "^2.1.4"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

Thank you !!