Create a *.service file (* is the service name, such as myscript.service)
Use root user and save this file to the /etc/systemd/system directory:
sudo cp myscript.service /etc/systemd/system/myscript.service
Then you can try to start the service with the following command:
sudo systemctl start myscript.service
Stop the service:
sudo systemctl stop myscript.service
Set automatic run at boot:
sudo systemctl enable myscript.service
The systemctl command can also be used to restart or disable it.

PrtSc: Take a screenshot of the entire screen and save it to the Pictures directory.
Shift + PrtSc: Take a screenshot of a certain area of the screen and save it to the Pictures directory.
Alt + PrtSc: Take a screenshot of the current window and save it to the Pictures directory.
Ctrl + PrtSc: Take a screenshot of the entire screen and save it to the clipboard.
Shift + Ctrl + PrtSc: Take a screenshot of a certain area of the screen and save it to the clipboard.
Ctrl + Alt + PrtSc: Take a screenshot of the current window and save it to the clipboard.
The screenshot will be automatically saved in the Pictures folder

DEBIX supports automatic mounting of USB storage devices, and it can also be mounted by modifying /etc/fstab;

Yes.

If you want to modify the startup animation, please provide the bmp picture for us to add to the kernel image.

Run hostnamectl to view the hostname of the current system
Use the following command to change the hostname:
hostnamectl set-hostname [YOUR NEW HOSTNAME]

debix, debix

5V power adapter. It depends on the power ability.

Provide a 5V3A power supply.

No