Manually mount second VirtualBox virtual disk in Ubuntu Server guest (no GUI)

Question

I use the VirtualBox UI to add a second virtual disk (belonging another VM) to my Xubuntu 18.04 guest. After I boot the guest I see a desktop icon named "20 GB Volume" with the tooltip "Removable Volume. Not mounted yet.". At this point df shows me

Filesystem     1K-blocks      Used Available Use% Mounted on
udev             1989308         0   1989308   0% /dev
tmpfs             403956      1044    402912   1% /run
/dev/sda1       61663020   6819780  51681232  12% /
tmpfs            2019768         0   2019768   0% /dev/shm
tmpfs               5120         4      5116   1% /run/lock
tmpfs            2019768         0   2019768   0% /sys/fs/cgroup
tmpfs             403952        12    403940   1% /run/user/1000

Double-clicking the desktop icon mounts the volume, after which it shows up in the df output as /dev/sdb1

Filesystem     1K-blocks      Used Available Use% Mounted on
udev             1989308         0   1989308   0% /dev
tmpfs             403956      1048    402908   1% /run
/dev/sda1       61663020   6819456  51681556  12% /
tmpfs            2019768         0   2019768   0% /dev/shm
tmpfs               5120         4      5116   1% /run/lock
tmpfs            2019768         0   2019768   0% /sys/fs/cgroup
tmpfs             403952        12    403940   1% /run/user/1000
/dev/sdb1       19478204   9814968   8650756  54% /media/gord/4554a2b5-26d3-4568-8127-41418ca654f4

My question: If I wanted to mount the volume on a guest running Ubuntu Server (no GUI) how would I do it without Xfce available to do the magic for me? I assume that it would involve the mount command, but

• where would I find the necessary information about the second virtual disk in the guest OS environment, and
• what would the mount command look like?