@Sridhar, Kailash Sharing the answer here directly from the post that @Anonymous shared above.
"you are configuring IIS re-write rules. as linux based app services do not use IIS, they have no effect (in fact web.config is ignored).
typically with linux, you would use ngnix to perform this feature.
https://www.nginx.com/blog/securing-applications-microsoft-azure-app-service-nginx-plus/"