You cannot "install" a BIOS like a regular APK. You need a Windows PC and specific tools:
Instead, search for on YouTube or reputable tech forums. You’ll find step-by-step guides using the right tools (Amlogic USB Burning Tool, PhoenixCard, or RKDevTool). ebox bios android download
Use this method if your box is still able to boot into the recovery menu. You cannot "install" a BIOS like a regular APK
Based on your issue, here are the real solutions: ebox bios android download
You might flash an Ebox BIOS for the S905X2 chip onto an S905X3 board. The device will boot, but your because the driver signatures don't match.