On

https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/linux-nginx?view=aspnetcore-2.0&tabs=aspnetcore2x

you show how to use journalctl, but not how to be able to filter using priority like Errors and higher. Also see question on stackoverflow.

https://stackoverflow.com/questions/50963198/how-to-filter-journalctl-logs-for-errors-for-aspnet-core-application-hosted-on-l