How to get children div via parent useRef in Reactjs

I have div like that

    const indexRef = useRef();
            <div className='indexBx' ref={indexRef}>
                <span className='active'>01</span>
                <span className='active'>02</span>
                <span className='active'>03</span>
            </div>

So now I want to change the secondary span classname via indexRef like something

indexRef.current.span:nth(2).className = ???

How can I do that

>Solution :

// change class of second child
 indexRef.current.children[1].className = 'passive'