Call to undefined function apcu_add()

Question

I'm currently working on an api which has been developed using Lumen 5.4. I'm trying to run this on my local XAMPP for Linux 7.4.3. But I keep getting the following error,

lumen.ERROR:
    Symfony\Component\Debug\Exception\FatalThrowableError:
    Call to undefined function xxx\Prometheus\Storage\apcu_add() in
    /opt/lampp/htdocs/xxx-api/vendor/xxx/php-prometheus-exporter/src/Storage/APCU.php:78

---

Current PHP version is 7.4.3. I have installed apcu along with apcu_bc and added the following to php.ini as well,

extension=apc.so
apc.enabled="1"

but I'm not seeing any apc related info in phpinfo.php page.

Any help is appreciated.