Is it possible to add 'formsStartSubmitting' on form element without JQuery?
I have this code currently 

<template>
  <div ref="GA4-script" />
</template>

<script>
export default {
  props: {
    formType: {
      type: String,
      default: '',
    },
  },
  mounted() {
    this.addEventHandler();
  },
  methods: {
    async addEventHandler() {
      await this.$nextTick();
      const parentForm = this.$refs['GA4-script'].closest('form');
      // eslint-disable-next-line no-undef
      $$epiforms(`.EPiServerForms#${parentForm.id}`).on('formsStartSubmitting', () => {
        if (window.dataLayer === 'undefined') { window.dataLayer = []; }
        // eslint-disable-next-line no-console
        window.dataLayer.push({
          event: 'form_submit',
          formName: this.getFormTitle(parentForm),
          formType: this.formType,
          customerType: this.getCustomerType(parentForm.id),
        });
      });
    },
    getFormTitle(form) {
      try {
        return form.getElementsByTagName('h2')[0].textContent;
      } catch (e) {
        return 'not found';
      }
    },
    getCustomerType(id) {
      // eslint-disable-next-line no-undef
      const radioButtons = $(`#${id} :input[type="radio"]`);
      // eslint-disable-next-line no-restricted-syntax
      for (const button of radioButtons) {
        if (button.checked === true && (button.value === 'Company' || button.value === 'Private Person')) return button.value;
      }
      return 'default';
    },
  },
};
</script>

Before $nextick I was adding window.onload eventlistener to mounted and I think it caused some race conditions which I think were solved with nexttick although not 100% sure. I'm also wondering if I could skip using JQuery if JQuery is not ready?. How would I replace this line with vanilla JavaScript ? I tried several ways but I'm missing something syntactically. Or if anyone could confirm that after nexttick JQuery should awalys be available, I think I can leave it at that.

$$epiforms(`.EPiServerForms#${parentForm.id}`).on('formsStartSubmitting', () => {})