Xiaomi will send you the code after you completed the form. I've submitted it yesterday, if I go to the unlock page now it will say it's being processed and I should have the code within 10 days (otherwise I should file a complaint).
For now I don't have a real need to unlock the BL, I'm really enjoying my Note 3, rooted it and changed the dpi, Google apps run perfect and English is fine. However running multi-lang would obviously be better, combined with TWRP, which give safety against bricks by being able to backup/restore.