In this case I've and array by using useState
const [acts, setActs] = useState([])
now the point is that I want to push item at 4th index in array, and it should look like this
['', '', '', '' ,'should be here', '', '']
So, the method I'm trying to do this is here
let actsArray = []
const [acts, setActs] = useState(actsArray)
const addItem = (index) => {
actsArray.splice(index, 0, 'Should be here')
setActs(actsArray)
}