What postgresql log entries do you need to monitor?

Question

PostgreSQL

I collect logs from postgresql through the elk stack.
Now it is possible to set up an alert for the presence of certain entries in the log.
Since I did not find any best practices or articles on similar topics, I would like to know which log entries you monitor or which entries are better to set alerts on.
Refused to write long queries, because I think it's better to do it through pg_stat_statments.
shutdown or recovery record is already being monitored.
We also monitor failed autovacuum tasks.
Also checkpoint frequency.