C# generate verification code to take random numbers and letters (improved version)

var text2 = "";
var random = new Random((int));
const string textArray = "23456789ABCDEFGHGKLMNPQRSTUVWXYZ";
for (var i = 0; i < iVcodeNum; i++)
{
text2 = text2 + (() % , 1);
}
return text2;