Start multiple virtualbox machines at startup

I have some virtualbox machines that I would like to start automatically at startup. Unfortunately, I have made several attempts, I always start only one: the first. The other boot options are cleared. I think it depends on some mate setting that sees the start of the Virtualbox program and deletes the other entries despite being the different parameters. I would like to avoid the creation of particular services or things.
Are there any solutions?
Command: /usr/bin/VBoxManage startvm UbuntuPCVM VM--type headless and /usr/bin/VBoxManage startvm Ubuntu-PC2-VM VM--type headless

How are you attempting to start these? Through a script? Can you install it into root's crontab with the @reboot option? I think I need to know a little more.

I have a script I use to start a number of VMWare workstation VMs, but I don't call it at startup.

I used "startup application". Unfortunately I correctly enter the commands and virtual machines to be started. Independently, the system or program "startup applications" deletes one of the two. So only one is started. probably because it verifies the same command and one of the two calls believes that it is duplicated. I attach some screenshots. I hope I have been clearer.
Can you bring me the script so that I can eventually use it too?

Maybe you could create a shell script containing the VM invocations one after the other, and then point Startup Applications to it? Something like this, perhaps?

# Start Virtualbox VMs 
/usr/bin/VBoxManage startvm UbuntuPCVM VM--type headless
/usr/bin/VBoxManage startvm Ubuntu-PC2-VM VM--type headless

Thank you for script! I will try it as soon as possible.