You should get a notification when the update hits your device. To manually check the update, head to Settings -> About phone -> System update -> Check for updates. Alternatively, you can download the update using the link given below and then install it using proper steps.
Redmi K30 5G (China) – V12.1.1.0.RGICNXM – Download Link
Changelog:
[System]
Stable MIUI based on Android 11
Steps to install the update
Download the update and save it in your device internal storage Open Settings -> About phone -> System update Click on menu (three dots at the top-right corner) and select “Choose update package” If you not getting the “Choose update package” option then click 7-8 times on the MIUI logo and now you will get the option Select the file you downloaded in the first step Wait for the update to install and then reboot the device
