Azure allows storing diagnostics logging to following storages:
- File System
- Blob Storage
Go to App Service > Activity Log. Here you can see the Subscription Level (Billing) information like Publishing, Stopping & Restart service etc.
Diagnose and solve problems
App Service logs
For application level troubleshooting we have to use the App Service logs. Set the Application Logging to On with Level to Verbose. You can also make Detailed error messages to On.
After enabling Application Logging & Detailed error messages you can view the App Service > Log Streaming window. This will give live logging information.
Try accessing the URL again and you should get the Logging text in the above window. Copy the text and Save as HTML file to view the Sub Level error code & Verbose information.
Advanced Tools (Kudu Console)
Open Advanced Tool (Kudu Console) > Debug > CMD
KUDU Console will give multiple log information like Application, IIS, Data, Detailed errors etc.