Downloading and installing a new Xbox 360 BIOS can be risky and may potentially damage the console. Here are some risks to consider:
If you are trying to update a physical Xbox 360 console offline, you can download official system update files directly from Xbox Support . How to Use Xenia (No BIOS Needed) Xbox 360 Bios Download
Xenia creates a xenia.config.toml file after the first run where you can adjust resolution and licensing settings. Are you setting up Xenia on a PC, or Downloading and installing a new Xbox 360 BIOS