Deploy ASP.NET Core Docker project - get a 405 error (locally in my IIS, web requests works). How to fix it?

Question

I am using .net core 3.1. With the help of docker I uploaded my code to heroku. but when i make a web request I get a 405 error with all my endpoints. (I cant see more details of the error)

using Get:

http://xxxx.herokuapp.com/api/pqrs/test/1315315

from visual studio code and also locally from my IIS everything works fine. but the problem occurs when I deploy to my server.

What am I doing wrong? this is the code of my controller:

    using System;
    using System.Collections.Generic;
    using System.IdentityModel.Tokens.Jwt;
    using System.Linq;
    using System.Security.Claims;
    using System.Text;
    using System.Threading.Tasks;
    using apiPQR.Contexts;
    using apiPQR.Entities;
    using apiPQR.Models;
    using Microsoft.AspNetCore.Authentication.JwtBearer;
    using Microsoft.AspNetCore.Authorization;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.Extensions.Configuration;
    using Microsoft.IdentityModel.Tokens;
    namespace apiPQR.Controllers
    {
        [ApiController]
        [Route("api/[controller]")]
        public class Pqrs : Controller

        {
            private readonly AppDbContext context;
            private readonly IConfiguration configuration;
            public Pqrs(AppDbContext context, IConfiguration configuration)
            {
                this.context = context;
                this.configuration = configuration;
            }
            [HttpGet, Route("test/{id}")]
            public PQRS Get(int id)
            {
                var num_pqrs = context.PQRS.FirstOrDefault(p => p.num_solicitud==id);
                return num_pqrs;
            }
        }

    }

update:

this is my Dockerfile

#See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base

WORKDIR /app

EXPOSE 80

EXPOSE 443

FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build

WORKDIR /src

COPY ["apiPQR.csproj", ""]

RUN dotnet restore "./apiPQR.csproj"

COPY . .

WORKDIR "/src/."

RUN dotnet build "apiPQR.csproj" -c Release -o /app/build

FROM build AS publish

RUN dotnet publish "apiPQR.csproj" -c Release -o /app/publish

FROM base AS final

WORKDIR /app

COPY --from=publish /app/publish .

ENTRYPOINT ["dotnet", "apiPQR.dll"]

At no time have I seen CORS issues or anything like that. just the 405 error.