On my first version 2018 supplied on a HD I just created a BiaB 2018 folder on my external SSD and copied everything from the original BiaB HD in that folder. I opened the app from the SSD, added it to the dock and have had no problems at all. All the updates were installed later on the SSD and have worked right off.

Mojave 10.14.6, iMac 4K, Logic Pro X, BiaB UltraPak 2019 Mac, Native Instruments A61.

Catalina 10.15, MacBook Air, Logic Pro X, BiaB Ultrapak 2019 Mac, Arturia Keystep.