How to install gparted live on grub boot menu?

[Bo Berglund]

I have a PC with these operating systems:
Windows 10
Ubuntu 20.04.3 Desktop
Ubuntu 20.04.2 Server

This is an EFI installation.

The boot menu was installed on the PC when I installed Ubuntu 20.04.3 Desktop 
in dual boot mode.
Then I also copied over my server to this disk using GParted on Ubuntu Desktop.
And I used update-grub on the Desktop to get the server on to the boot menu.

So this works OK now.

But whenever I need to take a backup of the PC I want to use GParted and I only 
have 2 options:
1) Start the Ubuntu Desktop and use GParted
This works OK except that the partition with the Desktop version itself is 
locked.
2) Start the PC from a GParted Live USB
This is very non-trivial to do since the only way I have found to do thios is 
to go into Windows and then 
use Shift-Start-Power-Reboot and select the USB drive from the presented 
possibilities.

I would like to have GParted Live as a separate item on the boot menu instead.
Googling has brought up these hits:

https://askubuntu.com/questions/1257868/booting-gparted-with-grub
https://gparted.org/livehd.php#live-hd-grub

But I find them very confusing to follow...
Is there some easy to understand way which will do this?

On Ubuntu Desktop:
- Create new 1GB ext4 partition /dev/somepart1 using GParted on Ubuntu
- sudo mkdir /mnt/gparted (create mount point)
- sudo mount /dev/somepart1 /mnt/gparted
- cd /mnt/gparted
- wget https://downloads.sourceforge.net/gparted/gparted-live-1.3.1-1-amd64.iso

Now I need to create the grub entry and this is where I have problems because 
of the mixup 
between grub and grub2 in the pages I have found.

Can someone help filling in the final part of the actions I need?
The end result should be to have a last line in the boot menu saying:

GParted Live

--
Bo Berglund
Developer in Sweden