How can I get notified for every Exception occurrence in Google App Engine?

I want to get notified (through email of slack channel) for every Exception occurence in my GAP services.

When I'm trying to create a notification through GCP Error Reporting, it seems like I'm being able to get one notification per incident (and not per occurrence), and that it is also being queried only once a day/hour/month.

I've also tried to create a policy in GCP Logs Monitoring based on log severity, but of course I don't get notified only for exceptions, and the slack notifications just announce that a threshold is being passed, without the actual data I want to get by push.

1. Any way I can make Error Reporting notify me per each occurance?

2. Is there any other internal tool by GCP that notify when event occurs? or should I use an external tool such as Epsagon/Operations (formally Stackdriver)?

So it seems like there is no availability for getting a pushed event on each exception occurrence, and since I didn't want to query it by pull (with ereport) or to get only new exceptions (through Stackdriver), I had to go with an external service such as Datadog.