I have had several Redmi phones. Yes, the current unlock process is a convoluted - You need a Xiaomi account. Then you need to toggle "unlock" in Developer settings. Then go to fastboot. Then while connected to your PC, you need the Xiaomi Unlock app to unlock the phone which you need to wait 2 weeks to happen. After 2 weeks, you go back to fastboot and the Xiaomi app, click Unlock and it is done.
(phew!)
It is tedious but not horrible. Once this is done, your bootloader is unlocked. You can then install your own custom recovery, custom rom, etc.
From most preferred... CrDroid, EvolutionX, LineageOS, Bliss ROM.