Cant use the script

[bitonchen]

i installed the dependencies but i always get this error:

releases.ubuntu.com has 12.04 14.04 16.04 18.04 19.04 20.04 20.10
use version > 18.04
--2021-01-31 11:05:14-- http://cdimage.ubuntu.com/releases/18.04/release/
Resolving cdimage.ubuntu.com (cdimage.ubuntu.com)... 91.189.88.247, 91.189.91.123, 91.189.88.248, ...
Connecting to cdimage.ubuntu.com (cdimage.ubuntu.com)|91.189.88.247|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Saving to: ‘/home/bitonchen/Downloads/index.html’

index.html [ <=> ] 22.12K --.-KB/s in 0.09s

2021-01-31 11:05:14 (258 KB/s) - ‘/home/bitonchen/Downloads/index.html’ saved [22649]

[sudo] password for bitonchen:
mount: /home/bitonchen/ubuntu-server-auto-install-master/mount.dSg: special device /home/bitonchen/Downloads/release does not exist.
cat: 'mount.dSg/.disk/*info': No such file or directory

ubuntu-server-auto-install: line 50: mount.dSg/.disk/*info: No such file or directory
umount: mount.dSg: not mounted.
ubuntu-server-auto-install: line 92: release-auto-install/isolinux/lang: No such file or directory
ubuntu-server-auto-install: line 93: release-auto-install/isolinux/isolinux.cfg: No such file or directory
ubuntu-server-auto-install: line 101: release-auto-install/boot/grub/grub.cfg: No such file or directory
cat: /home/bitonchen/.ssh/id_rsa.pub: No such file or directory
xorriso 1.5.2 : RockRidge filesystem manipulator, libburnia project.

Drive current: -outdev 'stdio:release-auto-install.iso'
Media current: stdio file, overwriteable
Media status : is blank
Media summary: 0 sessions, 0 data blocks, 0 data, 38.5g free
Added to ISO image: directory '/'='/home/bitonchen/ubuntu-server-auto-install-master/release-auto-install'
xorriso : UPDATE : 2 files added in 1 seconds
xorriso : FAILURE : Cannot find in ISO image: -boot_image ... bin_path='/isolinux/isolinux.bin'
xorriso : UPDATE : 2 files added in 1 seconds
xorriso : aborting : -abort_on 'FAILURE' encountered 'FAILURE'
Created release-auto-install.iso
Run test installation with:
qemu-img create -f qcow2 release-auto-install.qcow2 10G
qemu-system-x86_64 -smp 2 -enable-kvm -m 4G --cdrom release-auto-install.iso release-auto-install.qcow2