What does 'app index' mean in app review feedback?

[xrely]

Hi Everyone 

I got the following response from the app reviewer. Can someone help me understand the term app index?

Update your pricing information to include free trial time and charge details to comply with our requirements. See this screenshot for additional details, it doesn't have 30 days free trial from app index. See this screenshot as well for your reference on how the free trial should look like on the app.