what is the criteria caused my item to be rejected ?

How can I know what criteria that make Envato reject my item so I can avoid it next time this is what I got in email

"Here is the comment from your Envato Quality team reviewer:

This item has a nice concept, but doesn’t feature the required functionality and features to be approved as a premium item"

please tell me how can I have my items approved , this was my first item though

Can we take a look at your item? Do you have a live demo?

Actually no its not a theme I didn’t link to a live demo I make a php script that allows anyone to encrypt a text using the railfence algorithm I build it as a class

In this case, my suggestion is to take a look at Envato Common Rejection page: https://help.market.envato.com/hc/en-us/articles/202500934-Common-Rejection-Reasons-for-Envato-Market