I want to test my first “hello word” Anaconda addon program.

Firstly, I use this source code ( https://github.com/rhinstaller/hello-world-anaconda-addon/) ， and make a outfile updates.img. 

Then, I made a USB boot disk （CentOS 7.4）, and placed updates.img into the directory “images/”  of boot disk.

Then I used inst.updates=hd:/sdb4:/images/updates.img boot option, There isn't a new helloworld Category on the installation menu.

Is there anything wrong with steps above？  

Thanks.

edison