Because this is an uncommon board, you will not find it on official manufacturer websites. Instead, try:
Warning: Always virus-scan downloaded firmware. Many “20b3” images from unverified sources contain rootkits. Compare MD5 hashes if available. ---- K1006p9-mb-v1.0 20b3 Firmware
In Rockchip Upgrade Tool, click "Export Image" before writing anything. Save the parameter and uboot partitions separately. The 20B3 board has factory calibration data stored in a private vendor block (e.g., MAC address, touch calibration). Because this is an uncommon board, you will
Run this from a live USB on a working board: Warning: Always virus-scan downloaded firmware
cat /proc/cpuinfo # Identify the exact SoC
lsusb # List all USB peripherals
i2cdetect -y 0 # Find the touchscreen or RTC I2C address
Once you obtain a file (usually update.img, firmware.bin, or spi_flash.bin), compute its SHA-256:
sha256sum K1006P9_20B3_v2.1.bin
Compare with any hash posted by a trusted user. Do not flash if the hash is missing.