Hello Raj,
Check the App Service logs (Log stream and Application logs) in the Azure portal for errors to make sure your deployment was successful, and verify that all required environment variables, dependencies, and runtime versions are correctly configured. Additionally, confirm there are no networking issues (firewall rules or VNet misconfigurations) or resource limits (CPU, memory) affecting your app.
Restart the App Service, redeploy your application if necessary, and test locally to rule out environment-specific issues. If the problem persists, contact Azure Support with detailed logs for further assistance.
https://stackoverflow.com/questions/39510329/azure-web-app-not-accessible-stopped-working
https://learn.microsoft.com/en-us/azure/ai-foundry/how-to/troubleshoot-deploy-and-monitor