Ideally you’ll want to deploy an identical web app and supporting architecture in another region to combat DR scenarios with something like Front Door so you can benefit from priority routing if one region goes down.
Here’s a referenced architecture for that setup and how it’d look:
This is also a really great read in general, but specifically the heading around disaster recovery will go into detail for you on this subject around web apps as well:
https://learn.microsoft.com/en-us/azure/reliability/reliability-app-service?tabs=graph%2Ccli
Hope this helps, please mark as accepted if you feel it has.