Shawee subscription script

subscribe.js

// First we get the form instance and add an listener for the submit event
var form = document.querySelector('.form');
form.addEventListener('submit', function(e) {
    e.preventDefault();
    var serialized = $('#submitForm').serializeArray();
    var btnSend = document.querySelector('.btn-send');
    btnSend.setAttribute('disabled', '');
    btnSend.setAttribute('style', 'cursor: not-allowed');
    
    // then we build the POST request to shawee API with all the variables to fill in the participant profile
    fetch('https://api.shawee.io/api/graphql', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        query:
          'mutation ($person: AddPerson!, $participant: AddParticipant!) {\n  addPersonAsAParticipant(person: $person, participant: $participant) {\n    name\n    email\n    phone\n    __typename\n  }\n}\n',
        variables: {
          person: {
            name: serialized[0].value,
            email: serialized[1].value,
            cpf: serialized[2].value,
            phone: serialized[3].value,
            linkedin: serialized[4].value,
            github: serialized[5].value,
            facebook: serialized[6].value,
          },
          participant: {
            hackathonId: hackathonId,
            roleId: serialized[7].value,
          },
        },
        operationName: null,
      }),
    }).then(function() {
      e.target.classList.add('invisible');
      var feedback = document.querySelector('.feedback');
      feedback.classList.remove('invisible');
      var modalTitle = document.querySelector('.modal-header-title');
      modalTitle.innerText = 'Success!';
    });
  });