OTP code generator C# .Net

Sample C# code to get OTP Code

public static string GenerateOTPCode()
{
    char[] charArr = "0123456789".ToCharArray();
    string strrandom = string.Empty;
    Random objran = new();
    var properties = new Properties();
    for (int i = 0; i < properties.OTPLength; i++)
    {
        //It will not allow Repetation of Characters
        int pos = objran.Next(1, charArr.Length);
        if (!strrandom.Contains(charArr.GetValue(pos).ToString())) strrandom += charArr.GetValue(pos);
        else i--;
    }
    return strrandom;
}

Summary:

OTP Code generator