How to get base server address in an IHostedService

Question

In my ASP.NET Core web app I have an IHostedService object which performs some tasks periodically by using a timer.

Those tasks should retrieve the base server URL so I am trying this to do it:

Implemented StartAsync method:

public Task StartAsync(CancellationToken cancellationToken)
{
    _hostApplicationLifetime.ApplicationStarted.Register(
        () =>
        {
            _baseUrl = GetBaseUrl();
        });

    return Task.CompletedTask;
}

Where GetBaseUrl() method is:

private string GetBaseUrl()
{
    ICollection<string>? addresses = _server.Features.Get<IServerAddressesFeature>()?.Addresses ?? null;
    if (addresses != null && addresses.Count > 0)
    {
        return addresses.FirstOrDefault() ?? string.Empty;
    }
    return string.Empty;
}

After that code, the URL gotten by Addresses property is only one and strangely, it has a Kestrel port, My site is running under IISEXPRESS in port 44375.

How can I do it?

Of course, _server is a IServer and _hostApplicationLifetime is a IHostApplicationLifetime passed using DI into the hested service.