Creating Live USB for both 22.04 and 23.04

I have a Live USB with 22.04 and I want it to be able to run both 22.04 and 23.04. I'm a novice. Can I erase the USB, create two partitions then use Startup Disk Creator? I'm currently downloading those ISO files, so I can't just try it out. Also I only have one USB stick. I'm assuming I need two partitions, but that is just a guess.

I have the Ventoy app running on my target machine and showing 22.04 and 23.04 in the menu, but when I select either of these, I next get a black screen with no progress. I'll recopy the ISOs on the USB, but its not working yet. I doubt both my ISOs are corrupt, so I suspect there is a problem with Ventoy.

Multiboot Full Install Pendrive

Besides for a Persistent multiboot USB drive you can Fully install multiple OS to the drive. For advantages of each method see: https://askubuntu.com/a/1367263/43926.

Start by creating a Ubuntu Full install USB using this method: https://askubuntu.com/a/1403793/43926

At the GParted partitioning stage make an extra ext4 partitions for each additional OS you wish to install.

Once the Full install is complete, boot the installer USB for the next OS you want to install and install it to one of the extra ext4 partitions using the same BIOS/UEFI mode Ubuntu was installed in. See: https://askubuntu.com/a/960414/43926

When complete, boot the USB drive to Ubuntu and run sudo update-grub to add the new OS to Ubuntu's boot loader.

1. You can use Ventoy. Ventoy is a tool that runs one time to make a bootable flash drive. After that, you can add any ISO file to a USB drive's home directory to get it in Ventoy's USB drive boot menu.

2. you can use UNETBOOTIN to create multi bootable Live USB drive for Ubuntu and other Linux distributions.

   sudo add-apt-repository ppa:gezakovacs/ppa
   sudo apt-get update
   sudo apt-get install unetbootin
   

3. grml-rescueboot doesn't require usb drive, it will add iso file to your current system boot menu.

   The package does the following:

   • Creates a /boot/grml folder.

   • Automatically adds menuentries to the GRUB menu for any ISO files located in the /boot/grml folder. This is accomplished whenever the
     update-grub command is executed.

   • The created menuentry, when selected, provides submenu options on how to boot the ISO, including the "Try Ubuntu" and "Install" options.

   To use the grml-rescueboot option:

   1. Install grml-rescueboot

        sudo apt-get install grml-rescueboot
      

   2. Place bootable ISO files in the /boot/grml folder.

      • Since this is a system folder, the operation must be conducted as "root". For example, if the ISO is located in the user's Downloads folder, the command would be:

          sudo mv ~/Downloads/<filename.iso> /boot/grml/
        

   3. Update GRUB

        sudo update-grub
      

   reboot and sellect grml........iso from boot menu
   
   finally you can manually create USB drive contains multi Ubuntu versions, HBCD-PE-64 and multi Windows installation without any especial multiboot creation tool.