Separating power in Pi Zero when using the Pi as a HID that must be working without shuting down

Question

I asked an AI:

When you use raspberry pi zero w as a HID, is it necessary to connect the pi to a machine via a single micro usb cable, for the power and the data connectivity? Does that mean that when the machine shuts down the connected pi also gets shut down? I was planning to use the pi as a HID when the machine is showing a bios boot menu right after a reboot.

And the AI responds:

Yes, when using a Raspberry Pi Zero W as a Human Interface Device (HID), it is necessary to connect it to a machine via a single micro USB cable for both power and data connectivity. This is because the Raspberry Pi Zero W does not have built-in wireless capabilities and requires a wired connection for communication.

If the machine to which the Raspberry Pi Zero W is connected shuts down, the Raspberry Pi Zero W will also lose power and shut down as well, as it is powered through the micro USB cable. This means that if you're planning to use the Raspberry Pi Zero W as a HID during the BIOS boot menu right after a reboot, you will need to ensure that the machine remains powered on during that time for the Raspberry Pi Zero W to continue functioning as a HID.

This could involve using a separate power source, such as a USB power bank, to power the Raspberry Pi Zero W independently of the machine, or finding a way to keep the machine powered on during the BIOS boot menu.

Now, he said "power the Raspberry Pi Zero W independently of the machine" but how is that possible? Thanks.