How can I set a form as invalid dynamically?

I use wppb(https://wppb.me/) for my plugin and I#d like to set a form as invalid.

I can set a custom message with wpcf7_display_message, but I can’t set a form as invalid, with a red background, and stop submission.

I add action like this:

private function define_public_hooks()
{
$plugin_public = new Unitel_Sim_Registration_Public( $this->get_plugin_name(), $this->get_version() );
$this->loader->add_action( 'wpcf7_before_send_mail', $plugin_public, 'before_email_send', 10, 2 );
}

And then

public function before_email_send( $contact_form )
{
$submission = WPCF7_Submission::get_instance();
$posted_data = $submission->get_posted_data();
$email = sanitize_email($posted_data['uscr-email']);
$cvr = sanitize_text_field($posted_data['uscr-cvr']);
$customer = $this->customer_exists( $email, $cvr );

if ( is_null( $customer ) )
{
	$this->login_message('Customer not found');
	// I set a message, but it has a green background and form submits
	// I would like to show a message in a red background, indicating an error and stop it from submission
	// how can I do that?
}
}

public function login_message( $messages )
{
add_filter('wpcf7_display_message', static function ( $message, $status ) use ($messages) {
	return $messages;
},10,2);
}