https://docs.microsoft.com/en-us/archive/blogs/waws/azure-web-apps-error-403-this-web-app-is-stoppedThere are 3 conditions that can cause this error to be presented.
The site has reached a billing limit and your site has been disabled.
The Website has been stopped in the portal.
The Azure Website has reached a resource quota limit that applies to either Free or Shared scale modes.
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