It depends on which model you are talking about. As you might know the Fermzilla has three ranges:
FermZilla Flat Bottom - This fits
FermZilla All Rounder - The 30L Fits but not the 60L
FermZilla Conical Uni Tank - These do not fit unless you make some significant modifications.
If you need a fridge for fermenting I would wait until next year and then get the RAPT Fermenting fridge
Is RAPT a kegland service? Im assuming its rapt.io?