Open the RT809H operation interface, click [Smart Identification], select TYPE as EMMC, and Volt as 3.3V. Click settings, check EMMC Area in front of User/boot1/boot2/EXT_CSD, select VCCQ as 3.3V, then click write, choose the backup file, and select any one to start writing.
RT809H Programmer Taobao Link:
https://item.taobao.com/item.htm?id=551805435687
eMMC Programming Socket Taobao Link:
https://item.taobao.com/item.htm?id=560967621649
Copy the link to open Taobao on your mobile or browser