React change function but not class name

i have question,how can change className too? This is my test code, when i click on button it is ok and it change this state and change function, but it doesnt change main class in map? Can you give me some idea how can i fix it?

import '../Homepage/Body.css';
import './FAQ.CSS';
import React, {useEffect, useState} from 'react';
import InfoForPatPage from "./Informace";

function FaqPage (props) {


  const [Open,setOpen] = useState([]);
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState("");
  

  useEffect(() => {
    
  loadAsyncData();

}, []);


    const openClick = (items) => {
        items[3]=true;
        items[4]="faq-button open"
        console.log(Open)
    }

    const closeClick = (items) => {
        items[3]=false;
        items[4]="faq-button close"
        console.log(Open)
    }


    
    return (
        <div className="page">
        <InfoForPatPage />
            <div className="faq-container">
                <h2>   FAQ </h2>
                {Open.map(items =>  ( 
                <div className={items[3]? "a" : "b"} key={items[0]}>  
                    <button onClick={() => items[3] ? closeClick(items) : openClick(items)} id={items.id}  className={items[3] ? 'active' : ''}>
                  <p className="faq-button-text">{ items[1]}</p>
                     
                    </button>
                    <div className="panel fade-in-top"  >
                    <p>{ items[2] }</p>
                    </div>
                </div>))}

            </div>
       </div>
      );
    }