How to battle AI's better than Bronze

I’ve been battling a bunch of people but still I haven’t gotten the option. Also I saw silver ai once on blazing battle but I accidently clicked on a different one and when I came back it disapeared. Plz help!

I have played 240 players and won 224 of them.

Here is the link of the Silver AI: CodeCombat - Coding games to learn Python and JavaScript

You can challange the AI from that URL.