The specifically refers to a standard Android 7.1.2 (Nougat) configuration used across many "white-label" RK322x boxes.

Direct firmware downloads for the build on RK322x (RK3228/RK3229) boxes are primarily found on community forums and repository mirrors. This specific build version is commonly used for generic "MXQ Pro 4K" boxes and similar unbranded Rockchip-based devices. 📥 Firmware Repositories & Downloads

Since these devices are often generic, there is no single "official" download site. Instead, you can find compatible firmware and community-driven OS alternatives through these platforms: Generic RK322X (rockchip-rk322x) - postmarketOS Wiki