Device name：Redmi K40S / POCO F4

Codename：munch

Bootloader：You need to unlock the bootloader if you want to flash a rom into your phone via fastboot method, and your data could be deleted as you choose, please make sure you have backed up your personal data. , Apply for Bootloader Unlock here.

MIUI Roms：Yes , go to the MIUI site: Redmi K40S / POCO F4(munch) - MIUI Official ROMs