I am trying to store value in the global variable then pass it through Axios, but I can't store it in the variable. here is my code sample.

const voteSubmit = document.querySelector('#voteSubmit');
const votevalue = document.querySelectorAll('.votting_buttons button');

let voteNum;
votevalue.forEach((btn) => {
    btn.addEventListener('click', () => {
        voteNum = btn.dataset.votno;
    });
});

how could I store it?