It's inside the firmware-update folder ..If I remember correctly, it works only for cmi?
In ROM zip file Ifor my phone 've seen only boot.img that considering its size could be the recovery file.
Послато са Mi 10 помоћу Тапатока
I flash previous developer rom with twrp1206 renamed to recovery.img and replaced inside the firmware-update folder just to have it in partition and not having the 3.4.0 in recovery partition , even if it is not work without entering fastboot i prefer to have 1206 in recovery partition than 3.4.0 ..
Edit
CMI and LMI don't have issues with twrp ..