Thank you again, I would never think of that "let input = [...arguments]"

But why it's not working in VSC?

Uncaught TypeError: Cannot read property 'length' of undefined

I have changed your code to work with input.shift(), which takes each element of the array and doesn't need length or index.

Also make sure, with what input you are working with:

1: ['300', 'Captain Marvel', 'popcorn', 'Pepsi'], already comes in form of an array, does not need let input = [...arguments] and you should use function solve(input)

function solve(input) {}
solve(['300', 'Captain Marvel', 'popcorn', 'Pepsi']);

2: ('300', 'Captain Marvel', 'popcorn', 'Pepsi'), separate arguments not inside of an array (as is the case for this exercise), use function solve(...input) or let input = [...arguments] to create an array with the necessary elements. When using [...arguments], function solve() can remain empty.

function solve(...input) {}
OR
function solve() {}
let input = [...arguments]
solve('300', 'Captain Marvel', 'popcorn', 'Pepsi');

Otherwise, your code version with length/index works this way:

function solve() {
    let input = [...arguments]
    let sumVoucher = Number(input.shift());
    let index = 0;
    // let total = 0;
    let movie = 0;
    let otherProduct = 0;
    // let currentProduct = input.shift();
    let currentProduct = input[index];

    // while (currentProduct !== 'End') {
    while (index < input.length) {

        if (currentProduct === "End") {
            break;
        }
        let total = 0;

        if (currentProduct.length > 8) {
            total += (Number(currentProduct.charCodeAt(0)) + Number(currentProduct.charCodeAt(1)));

            if (total <= sumVoucher) {
                movie++;
            } else {
                break;
            }
            // sumVoucher -= total;

        } else {

            // if (Number(currentProduct.charCodeAt(0)) >= 97 &&
            //     Number(currentProduct.charCodeAt(0)) <= 122)
            total = Number(currentProduct.charCodeAt(0));
            if (sumVoucher >= total) {
                otherProduct++;
                // sumVoucher -= total;
            } else {
                break;
            }
        }
        sumVoucher -= total;

        // currentProduct = input.shift();
        index++;
        currentProduct = input[index];
    }
    console.log(movie);
    console.log(otherProduct);
}

Best,