Azure App Service is a service used to create and deploy scalable, mission-critical web apps.
@Jassim Al Rahma Thanks for reaching here! Could you please confirm, When you have entered the values, then make sure you bypass the Cloudflare. This is required to add the custom domains to the Azure App service. The proxy status must be grey.
Suggest you look into this document- How to set up a custom domain name for an Azure web app using Cloudflare
Let us know if issue remains.