I have an environment setup with multiple azure web apps across multiple Azure service plans.
I'm now retrospectively trying to add an azure WAF between the wider internet and the websites.
I have created a WAF, but am now struggling to understand whether it is currently possible to continue to use the *.azurewebsites.net app addresses and route traffic through the WAF?
Is it possible to use the built in *.azurewebsites.net app service addresses as the external entry point to the Azure WAF?
I think I understand your question, what you need to do is route the traffic to the application gateway add azure web app as the backend to the application gateway.
https://learn.microsoft.com/en-us/azure/application-gateway/create-web-app
you cannot azure *.azurewebsites.net as an endpoint for application gateway