App.jsx

import { createNewListItem } from "./Actions";

const { state, dispatch } = useContext(Store);
const input = useRef();

const onFormSubmit = event => {
  event.preventDefault();

  createNewListItem({
    dispatch,
    payload: { listItemValue: input.current.value }
  });
};

return (
  <main>
    <h1>To do list</h1>
    <form onSubmit={onFormSubmit}>
      <input type="text" ref={input} />
      <input type="submit"/>
    </form>
    
    // ...
  )