How to add an environment to an existing Azure app?

Hi everyone,

I'm new to Azure so this is probably going to be a very basic quesiton for someone, but how can I make a new environment (e.g. staging) for an existing app?

We have a live app (app service) but our main branch has several commits that we want to push to a test environment for testing and then push to live.

I've inherited this project. So far they've just been hoping for the best and then pushing to production and testing there!

I couldn't see anything under the app to add environments to it. Can anyone point me in the right direction?

Thanks in advance!