Azure App Service Logs. Enable the filesystem logs on azure portal. To enable application logging for windows apps in the azure portal, navigate to your app and select app service logs.
One of the most powerful (yet least used) diagnostic features of azure app service is the failed request tracing feature. Azure app service is integrated with azure monitor which makes many app service logs available in azure monitor and azure log analytics. Navigate to the app service to which you would like to enable the web server logs and go to “all settings” and click on “diagnostic log” as shown below.
In the resources array of the resource for which you want to enable diagnostic logs, add a resource of type [resource namespace]/providers/diagnosticsettings.
In order to take advantage of this, you'll need to log into your azure account and go to your app service that you created and look under monitoring then you will see log stream. One of the most powerful (yet least used) diagnostic features of azure app service is the failed request tracing feature. We have added a new log type for asp.net web apps on windows (asp.net core support is not yet supported). Select on for either application logging (filesystem) or application logging (blob) , or both.