2chBackAPI/Program.cs

using NeDvachAPI.BufferControllers;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();

builder.Services.AddEndpointsApiExplorer();

builder.Services.AddCors(setup =>
{
    setup.AddDefaultPolicy(policyBuilder =>
    {

        policyBuilder.WithOrigins("http://www.vdk2ch.ru:4200").WithMethods("GET", "POST").WithHeaders("*");
        policyBuilder.WithOrigins("https://www.vdk2ch.ru/").WithMethods("GET", "POST").WithHeaders("*");
        //policyBuilder.WithOrigins("http://localhost:4200").WithMethods("GET", "POST").WithHeaders("*");
    });

});

var app = builder.Build();

if (app.Environment.IsDevelopment())
{

}

app.UseCors();

app.UseAuthorization();

app.MapControllers();

app.UseHttpsRedirection();

if (BufferFill.FillBuffer("b"))
{
    Console.WriteLine("Ready for work.");
    app.Run();
}
else Console.WriteLine("Ошибка буферизации, проверьте доступность базы данных.");