Answer by Meysam Ghorbani for Convert a hex string to base64

public string HexToBase64(string strInput){    try    {        var bytes = new byte[strInput.Length / 2];        for (var i = 0; i < bytes.Length; i++)        {            bytes[i] = Convert.ToByte(strInput.Substring(i * 2, 2), 16);        }        return Convert.ToBase64String(bytes);    }    catch (Exception)    {        return "-1";    }}

On the contrary: https://stackoverflow.com/a/61224900/3988122