I am hosting an asp.net core api on Heroku using Docker and github actions.

When the actions runs, everything is fine and the app is deployed. After I go to the url, I have an **Application Error** message.
Here is the concerned part in my logs

```
2022-02-17T16:41:54.949789+00:00 app[web.1]: [16:41:54 DBG] Failed to bind to http://[::]:80 (IPv6Any). Attempting to bind to http://0.0.0.0:80 instead.
2022-02-17T16:41:54.966069+00:00 app[web.1]: Unhandled exception. System.Net.Sockets.SocketException (13): Permission denied

```

After some searchs, I have found [this post](https://habr.com/en/post/450904/), [this previous question](https://stackoverflow.com/questions/59434242/asp-net-core-gives-system-net-sockets-socketexception-error-on-heroku) and also [this one](https://stackoverflow.com/questions/51004285/net-core-on-heroku-with-docker) saying to set the port in the Program.cs file or to set `ASPNETCORE_URLS=http://*:$PORT` in the Dockerfile. I have tried both but nothing worked.
Here is my Dockerfile

```
FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
WORKDIR /app

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY ["PeerNotation.Api.csproj", "."]
RUN dotnet restore "PeerNotation.Api.csproj"
COPY . .
WORKDIR "/src"
RUN dotnet build "PeerNotation.Api.csproj" -c Release -o /app/build
FROM build AS publish
RUN dotnet publish "PeerNotation.Api.csproj" -c Release -o /app/publish
FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "PeerNotation.Api.dll"]

```

and the code snippet from my Program.cs file

```cs
var port = Environment.GetEnvironmentVariable("PORT");
builder.WebHost.UseUrls($"http://*:{port}");

```

(I have tried to log the port and it is never null)