Creating a crypted persistence

I am having troubles with creating an encrypted persistence. I followed the guide posted by rowie in this thread Encrypted-Persistence USB Parrot Security 4.7
But I keep getting the following error

Device /dev/ is not compatible.
Command failed with code -4 (wrong device or file specified).
Device /dev/ is not compatible.
mke2fs 1.45.6 (20-Mar-2020)
The file /dev/mapper/parrot does not exist and no size was specified.
e2label: No such file or directory while trying to open /dev/mapper/parrot
Couldn’t find valid filesystem superblock.
mount: /mnt/parrot: special device /dev/mapper/parrot does not exist.
umount: /dev/mapper/parrots: no mount point specified.

Can anyone help me?

Thanks in advance.