How to set up a log monitor in Datadog to alert on a specific error message within extendedStackTrace?

I'm currently working on setting up log monitoring in Datadog, and I'm trying to create a log monitor that alerts me whenever a specific error message occurs within the extendedStackTrace field of my logs. Specifically, I want to receive alerts when the message status: 407 Proxy Authentication Required is detected within the extendedStackTrace.

Here's a breakdown of what I'm aiming to achieve:

Log Scenario:

extendedStackTrace
io.netty.handler.proxy.HttpProxyHandler$HttpProxyConnectException: 
http, basic, <URL PATH WITH PROXY SERVICE>m/<unresolved>:443, status: 407 Proxy Authentication Required

1. My logs contain entries with extendedStackTrace, which includes detailed information about exceptions or errors that occurred in my application.

2. Target Error Message: I'm interested in detecting the occurrence of the error message status: 407 Proxy Authentication Required within the extendedStackTrace.

3. Alerting Requirement: I need to configure a log monitor in Datadog that triggers an alert whenever the specified error message is found in the extendedStackTrace field of any log entry.

Here's what I've tried so far:

• I've explored the Log Analytics feature in Datadog but haven't been able to figure out how to specifically target the error message within the extendedStackTrace field.

• I've attempted to create log queries using the "source" field to filter logs from the relevant source, but I'm unsure how to precisely match the error message within the extendedStackTrace.

• Could someone provide guidance on how to set up a log monitor in Datadog to achieve this specific alerting requirement? Any insights, tips, or examples would be greatly appreciated!