querySelector dows not work on event.target

I have onClick function but I can not access to its childeren elements from event

<div className="sortingBy" onClick={openSoring}>
<div className="checkBox" ></div>
</div>

my function

const openFilter=(e)=>{
        e.target.querySelector('.checkBox').classList.toggle('active')
    }

these codes are in react .

after using that code it get this error

e.target.querySelector(...) is null

how can I access to children elements from event variable in onClick propertie