In order to read the value in the <input> you can make it a controlled component by passing the current value as a string, and listening to the onChange event of the input.
<input
value={currentValue} // ...force the input's value to match the state variable...
onChange={e => updateValue(e.target.value)} // ... and update the state variable
/>
You can keep the value in another state variable of your App.tsx component.
useState()<input> into a controlled component by passing value and onChange props.