Going from openmediavault to Umbrel

actually running a OMV5 on a, i would like to move to UmbrelOS.
I’m using an HDD for storing personal datas and this one is mounted as a casual EXT4 drive, no RAID or anything.
My question is : moving onto UmbrelOS, will I have to format the disk to mount it or can I just plug and add it as an existing file system?