AWS Cloud9 - IP PORT to view over internet

Hello everyone,
I’m finishing the phoenix installation to use AWS Cloud9 as a development environment.
When using the
$ iex -S mix phx.server, no errors:

[info] Running PentoWeb.Endpoint with cowboy 2.9.0 at (http)
[info] Access PentoWeb.Endpoint at http://localhost:4000

Anyone who has used it knows that the port must be changed to 8080 or 80 in dev.exs

Even so, I can’t see the preview or open using the generated url.

Any suggestion?

Can I share the environment if someone wants to edit something, need IAM username