ACF confirm password validation

index.php

<?php
add_filter('acf/validate_value/name=user_password_confirm', 'my_validated_password_filter', 10, 4);
function my_validated_password_filter($valid, $value, $field, $input) {
  if (!$valid) {
    return $valid;
  }
  // field key of the field you want to validate against
  $password_field = 'field_5de8dff728aa2';
  if ($value != $_POST['acf'][$password_field]) {
    $valid = 'Does Not Match Password';
  }
  return $valid;
}