The Azure Portal has changed how they issue certificates. I have not been able to figure out how to secure the www of my app service domain name. I was able to apply a new cert to the root domain jasonrsmithmusic.com but not

======================================= Update: Made progress based on an answer below but the cert is still listed as invalid.
CodePudding user response:
I tried to reproduce the same in my environment added www.subdomain successfully.
Note: To map a subdomain www.jasonrsmithmusic.com ensure you should use A record instead of CNAME record like below.

To resolve this issue, you need to add a new custom domain name along with www.jasonrsmithmusic.com I have one previous custom domain name as travwebapp.com I use this custom domain as www.travwebapp.com like below.
And added a service managed certificate.

To know more in detail please check this reference
Map existing custom DNS name - Azure App Service | Microsoft Learn
Add and manage TLS/SSL certificates - Azure App Service | Microsoft Learn





