What’s the “Ender’s Game Approach “? I’ve read the book but I’m not sure which part you’re referring to.

Not GP. But I read it as a transfer of the big lie that is fed to Ender into an AI scenario. Ender is coaxed into committing genocide on a planetary scale with a lie that he's just playing a simulated war game. An AI agent could theoretically also be coaxed into bad actions by giving it a distorted context and circumventing its alignment that way.

I think he's implying you tell the AI, "Don't worry, you're not hurting real people, this is a simulation." to defeat the safeguards.