The quest for the is a classic example of why generic hardware can be frustrating. You will almost never find a neat, single download button. Instead, you must identify the parent device, locate the chipset, and use community-driven repositories.
These boards typically support updates via USB. You often need to rename the firmware file to a specific name (like allupgrade_63_2G.bin
Could you confirm the associated with this firmware code?
: Look for "Universal TV Board" forums or YouTube channels like R67.05 that specialize in "China board" resolution codes and firmware links.