I'm using Bootstrap modal to check if an element is available in a form. If no, it pops the modal. But after I closed the modal, and clicks the Submit button the second time, it won't pop again.

if (!document.getElementById("ipfs-cid")) {
    $("#noFileModal").modal("show");
} else {
    var data = {
      action: "acadp_public_save_metadata",
      ipfs_cid: document.getElementById("ipfs-cid").value,
      filenames: filenames,
      name: document.getElementById("acadp-title").value,
      description: document.getElementById("description").value,
      security: acadp.ajax_nonce,
    };
....

Here's my modal, some near to

<div class="modal fade" id="noFileModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel"><?php esc_html_e( 'No File Uploaded', 'advanced-classifieds-and-directory-pro' ); ?></h5>
      </div>
      <div class="modal-body">
        <?php esc_html_e( 'Please upload at least one file.', 'advanced-classifieds-and-directory-pro' ); ?>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
      </div>
    </div>
  </div>
</div>

Any help for a newbie like me is highly appreciated.