The script is telling you what the problem is... It either can't find the specified directory it needs, or if it exists, it can't write to it. I believe that path name should be the complete path to your cgi-bin directory or it won't work properly.

In the sample config file provided:

$progdir = "/home/httpd/cgi-bin";

Needs to be the complete path to your program directory. If you didn't specify the complete path and make it writeable by the Web server as per the instructions, the program won't be able to create the ojauth sub-directory it needs in order for the script to function.