I work with a MBP 15" (2019 eight core) and an USB HDD partitioned with an APFS encrypted volume.
Yesterday, after a regular power off of my MBP, I plugged in my external USB disk and I got an error message saying that Mac was unable to mount the disk and asking me to format it. In Disk Utility, this disk figure as Seagate ST4000LM024-2AN17V - USM external physical disk - Master Boot Record (MBR).
I tried from terminal to run
diskutil list and that showed me the following:
/dev/disk2 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *4.0 TB disk2 1: 0xEE 2.2 TB disk2s1
In the meantime, I found a software (iBoysoft Data Recovery) that had found my APFS encrypted partition and that is recovering my data, but I'm wondering how can I mount/restore this partition using terminal?