Crashes
We don't recommend crashes to be recorded and seen at an App environment level as it will be too fragmented for your team to manage. So you can signup for a crash reporting service and use it as your central store for recording crashes.
Sentry is the most popular choice today. There are also other prominent tools like BugSnag which you can explore and decide if they will be a better fit for your team.
You can signup for an account in one of these services and embed their sdk in Front-end and Back-end codebase to record crashes. Every unique application you make is usually modelled as a project in these crash reporting tools and crashes are recorded with environment tag.
For environment tag, you can use name like production, staging, customer-1, customer-4, etc., to identify which environment saw the crash. This tag name can be sent to your app environment via Helm values / environment vars while you create/deploy on the app environment. See Environment vars to know more.