The Stable update OS2.0.121.0.VOLCNXM has been officially released for Redmi Turbo 4 Pro (codename is onyx). Before updating, please make sure you have downloaded the exact ROM matching your Xiaomi phone/tablet. In Fastboot mode, you can check model code by typing fastboot getvar product in cmd/shell.
The firmware files posted here are all official Xiaomi MIUI or HyperOS ROM, xiaomiROM.com do not own and never modified those firmwares，you will always download the file from Xiaomi server.
You may interest in those contents: Redmi Turbo 4 Pro ROM Topics Xiaomi Devices Index
Download Redmi turbo 4 pro (onyx) China HyperOS OS2.0.121.0.VOLCNXM Fastboot ROM with Android 15.0. Firmware size is 10.6 GB.
Download Redmi turbo 4 pro (onyx) China HyperOS OS2.0.121.0.VOLCNXM Recovery ROM with Android 15.0. Firmware size is 7.9 GB.