Why my form only work in chrome when Js is active?

To submit my form, the user need choice the price of your ticket by html droplist.

Here is JS the code:

var ticket = document.getElementById('ticket-box'); var member = document.getElementById('member'); var form = document.getElementById('form');  form.style.display = 'none'; ticket.style.display = 'none';  member.addEventListener('change', function() {   var chosen = member.options[member.selectedIndex].index;     if(chosen == 1) {     form.style.display = 'inline-block';     ticket.style.display = 'inline-block';     form.selectedIndex = 2;     form.options[0].style.display = 'none';     form.options[1].style.display = 'none';     form.options[2].style.display = 'inline-block';     form.options[3].style.display = 'inline-block';     form.options[4].style.display = 'none';     form.options[5].style.display = 'none';  $  (function() {    $  ('#btnget').click(function(e) {        let formValido =  document     .getElementById("formulario")     .checkValidity();        if(formValido){          $  ("#formulario")          .attr("action", $  ('#form').val())          .submit();       }    }) });   }     }); 

This only works in chrome (email is comming only in chrome).

Why is this happening?

form link: http://www.congressoprotecaodados.com.br/inscricao/form22.html