src/PicoAuthPlugin.php
public function onPageRendering(&$templateName, array &$twigVariables)
    {
        $twigVariables['auth']['plugin'] = $this;
        $twigVariables['auth']['vars'] = $this->output;

        // Variables useful only in successful execution
        if (!$this->errorOccurred) {
            $twigVariables['auth']['user'] = $this->user;

            // Previous form submission
            $old = $this->session->getFlash('old');
            if (count($old) && isset($old[0])) {
                $twigVariables['auth']['old'] = $old[0];
            }
        }
    }
public function onPageRendering(&$templateName, array &$twigVariables)
    {
        $twigVariables['auth']['plugin'] = $this;
        $twigVariables['auth']['vars'] = $this->output;

        // Variables useful only in successful execution
        if (!$this->errorOccurred) {
            $twigVariables['auth']['user'] = $this->user;

            // Previous form submission
            $old = $this->session->getFlash('old');
            if (count($old) && isset($old[0])) {
                $twigVariables['auth']['old'] = $old[0];
            }
        }
    }
Pico API event

Makes certain variables accessible in the twig templates

@param string $templateName Name of the twig template file
@param array $twigVariables Twig variables