Azure web app for container - failed during startup - didn't respond to HTTP pings
When enforcing HTTPS at the App Service level, TLS termination will happen and traffic will be routed to your container port so there's no need to enforce TLS from your container.
If your container listens on another port (ex: 8081), simply set the WEBSITES_PORT application setting to that port number. App Service will listen on port 80 and forward traffic to your container port.