Error when implementing Swagger

Question

I am trying to implement Swagger in my application but I got the error by uploading the application

I did it by following the microsoft documentation, but, I did not succeed. It seems a very generic error, so I ask for help. Here’s my Swagger configuration class:

public static class SwaggerConfig
    {
        public static IServiceCollection AddSwaggerConfig(this IServiceCollection services)
        {
            services.AddSwaggerGen(c => 
            {
                c.SwaggerDoc("v1", new Microsoft.OpenApi.Models.OpenApiInfo
                {
                    Version = "v1",
                    Title = "TestApi",
                    Description = "Primeira versão da API"
                });
            });
            return services;
        }

        public static IApplicationBuilder UseSwaggerConfig(this IApplicationBuilder app)
        {
            app.UseSwagger();
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("swagger.json", "v1");
            });
            return app;
        }
    }

My Startup:

        public void ConfigureServices(IServiceCollection services)
        {
...
            services.AddControllers();
            
            services.AddSwaggerConfig();
..
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
{
  

    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
        
    }

    app.UseRouting();

    app.UseCors("MyPolicy");
   
    app.UseSwaggerConfig();
    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
    });


}

}