the form still gets submitted when VAT check doesn’t match

I have purchased the Geissweb VAT checker, But it doesn’t verify.

If the ZIP code from the VAT matches the ZIP code from the delivery address.

So, I created this code, but when it doesn’t match, the form still gets submitted.

Here’s my code ->

<?php
/**
 * @var Template $block
 * @var RemarktCustomerViewModelCustomerMenu $viewModel
 */

use MagentoFrameworkAppBootstrap;
use MagentoFrameworkAppFilesystemDirectoryList;
use MagentoFrameworkAppResourceConnection;
use MagentoFrameworkViewElementTemplate;

try {
    require BP . '/app/bootstrap.php';

    $params = $_SERVER;
    $params[Bootstrap::PARAM_REQUIRE_MAINTENANCE] = true;

    $bootstrap = Bootstrap::create(BP, $params);

    $objectManager = $bootstrap->getObjectManager();
    $objectManager->get('MagentoFrameworkAppState')->setAreaCode('frontend');
    $connection = $objectManager->get(ResourceConnection::class)->getConnection();

    // Replace 'vat_validation' with the actual table name
    $tableName = $connection->getTableName('vat_validation');

    // Replace 'vat_id' with the actual column name
    $selectVatId = $connection->select()
        ->from($tableName, 'vat_id')
        ->limit(1);
    $selectVatAddress = $connection->select()
        ->from($tableName, 'vat_trader_address')
        ->limit(1);

    $vatId = $connection->fetchOne($selectVatId);
    $VatAddress = $connection->fetchOne($selectVatAddress);
    $VatAddress = str_replace(array("r", "n"), ' ', $VatAddress);

    
} catch (Exception $e) {
    // Handle any exceptions that occur
    
}

?>
 <script>
  document.getElementById("form-validate").addEventListener("submit", function(event) {
    event.preventDefault(); // Prevent form submission
    var BTWnummer = document.querySelector('[name="vat_id"]').value;
    var postcode = document.getElementById("zip").value;
    console.log("btw +", BTWnummer);
    if (BTWnummer !== "" && postcode !== "") {

    var match = compareFormData(BTWnummer, postcode);
    var resultElement = document.getElementById("result");

    if (match) {
        console.log('fo423t');
        return  resultDiv.innerHTML = "fo423t";
    } else {
        console.log("<div class='mage-error'>Postcode van het BTW nummer komt niet overeen met het ingevulde postcode</div>");
        return  resultDiv.innerHTML = "<div class='mage-error'>Postcode van het BTW nummer komt niet overeen met het ingevulde postcode</div>";
    }
}
  });

  function compareFormData(formBTWnummer, formPostcode) {

    // JavaScript code for comparison
    var phpName = "<?php echo $vatId; ?>";
    var phpPostcode = "<?php echo $VatAddress; ?>";

    var containsSubstring1 = phpName.includes(formBTWnummer);
    var containsSubstring3 = phpPostcode.includes(formPostcode);
    
    if (containsSubstring1 && containsSubstring3) {
    console.log('goe5d');
    return true;
  } else {
    console.log('fo7ut');
    return false;
  }
}
</script>