Clear Craft CMS cache after Entry save event

module.php

<?php 

use yii\base\Event;
use Craft;
use craft\elements\Entry;

Event::on(
    Entry::class,
    Entry::EVENT_AFTER_SAVE,
    function(ModelEvent $event) {
        $entry = $event->sender;
        //Only flush cache when certain sections are saved
        if ( $entry->sectionId == 2 || $entry->sectionId == 8 ) {
            Craft::$app->getCache()->flush();
        }
    }
);