Create a customize alerte

Hi,
I need to create an alert who everymonth (for example) sending a message like “certificate expired”.
is it possible ?

Thank you

Not by default as it falls outside SNMP monitoring,

LibreNMS supports Nagios, so it might be possible to alert via Nagios integration

#https://docs.librenms.org/Extensions/Services/
#https://www.linuxincluded.com/monitor-for-expired-ssl-tls-certs-with-nagios/