React controlled vs. uncontrolled input form

First of all consider I'm fairly new to react.

I'm building a form with a field is an input. When entering the text into the input I recieve a message saying

Warning: A component is changing an uncontrolled input to be controlled

I look into the docuemnentaion but I'm not able to understand why it behaves like that. Can some one help me understand?

here is the input field

<div>
      <input type="text"
       name = 'brand'
       onChange = {(e) => inputChange(e)}
       value = {submit.brand}
       required />
    </div>

here is the function to handle it

{submit, SetSubmit} = useState([)
const inputChange = (e) => {
const { name, value } = e.target;
setSubmit(submit => ({...submit, [name]: value}))}

many thanks in advance for helping me understand

You can refer here for usage of controlled inputs in functional component.

You are initializing the state incorrectly,

const [submit, SetSubmit] = useState('');

Also, the onChange event should be handled as

   <div>
      <input type="text"
       name = 'brand'
       onChange = {inputChange}
       value = {submit}
       required />
    </div>

And function as,

const inputChange = (e) => {
  setSubmit(e.target.value)
}

In case of multiple inputs, please refer the following example :

import React, { useState } from "react";

const initialValues = {
  company: "",
  position: "",
  link: "",
  date: "",
  note: "",
};

export default function Form() {
  const [values, setValues] = useState(initialValues);

  const handleInputChange = (e) => {
    const { name, value } = e.target;
    setValues({
      ...values,
      [name]: value,
    });
  };

  return (
        <form>
          <input
            value={values.company}
            onChange={handleInputChange}
            name="company"
            label="Company"
          />
          <input
            value={values.position}
            onChange={handleInputChange}
            name="position"
            label="Job Title"
          />
           // ... Rest of the input fields
          <button type="submit"> Submit </button>
        </form>
  );
}