app/bundles/CoreBundle/Twig/Extension/VersionExtension.php

<?php

declare(strict_types=1);

namespace Mautic\CoreBundle\Twig\Extension;

use Mautic\CoreBundle\Helper\AppVersion;
use Twig\Extension\AbstractExtension;
use Twig\TwigFunction;

class VersionExtension extends AbstractExtension
{
    public function __construct(
        private AppVersion $appVersion
    ) {
    }

    public function getFunctions()
    {
        return [
            new TwigFunction('mauticAppVersion', [$this, 'getVersion']),
        ];
    }

    public function getVersion(): string
    {
        return $this->appVersion->getVersion();
    }
}