DD.WellWorkover.Cloud/AsbCloudWebApi/Extensions.cs

using AsbCloudDb.Model;
using System.Security.Claims;

namespace AsbCloudWebApi
{
    public static class Extensions
    {
        public static int? GetCustomerId(this ClaimsPrincipal user)
        {
            var claimIdCustomer = user.FindFirst(nameof(User.IdCompany));
            if (claimIdCustomer is null)
                return null;

            return int.TryParse(claimIdCustomer.Value, out int uid)
                ? uid
                : null;
        }
    }
}