GlobalCus.cs

namespace Banking_App
{
    public class GlobalCus
    {
        public static string GenerateNumber(int count)
        {

            var random = new Random();
            var randomIntegers = new int[count];

            for (int i = 0; i < randomIntegers.Length; i++)
                randomIntegers[i] = random.Next(0, 10);

            return string.Join("", randomIntegers);

        }

        public static string GenerateId()
        {
            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

            var charArr = chars.ToCharArray();
            var random = new Random();
            random.Shuffle(charArr);

            return  string.Join("", charArr)[..6];

        }

    }
    static class RandomExtensions
    {
        public static void Shuffle<T>(this Random rng, T[] array)
        {
            int n = array.Length;
            while (n > 1)
            {
                int k = rng.Next(n--);
                (array[k], array[n]) = (array[n], array[k]);
            }
        }
    }

}