Hello,
Since the local email service is disabled on your servers, the recommended approach is to configure an external SMTP relay in Plesk. This allows Plesk to send all notification emails (including update/microupdate availability) through an external mail provider instead of the local mail...
Hi
Could you try setting it using "Run command" setting like this?
/opt/plesk/php/8.4/bin/php -c /var/www/vhosts/system/example.com/etc/php.ini /var/www/vhosts/example.com/httpdocs/your-script.php