Always use Raspberry Pi Imager to flash microSD cards, and in this case to install MotionEye OS on any model of Raspberry Pi.
The tool is fool-proof. It runs on most operating systems, including Windows and Mac OS.
This guide assumes you have:
microSD Card
USB microSD Card Adapter
Step 1. Download Raspberry Pi Imager
Download and install Raspberry Pi Imager following the directions
Step 2. Insert microSD Card
On my Mac, read/write times are faster when I use a USB microSD card adapter, rather than the large SD Card adapter.
Insert the SD Card into the adapter, and insert the adapter into a USB slot.
Step 3. Get MotionEye OS Image
Go to https://github.com/ccrisan/motioneyeos/releases
Scroll down to Latest Release
Click on an appropriate image, such as, motioneyeos-raspberrypiM-VVVVVVVV.img.xz, which downloads the image, where
M = model of Raspberry Pi
VVVVVVVV = version number of MotionEye OS
Once downloaded, open a Finder window and unzip using The Unarchiver, which creates a new file without the .xz extension
Step 4. Launch Imager
Launch the Raspberry Pi Imager app
On Mac, select Finder, New File Window, Applications, scroll to Raspberry Pi Imager and open.
I use Raspberry Pi Imager all the time so I pinned it to the Dock.
Step 5. Write (aka Flash or Burn) the image to the microSD Card
Imager has three steps:
Select a raspbian image
Select Use Custom
Go to Downloads and select the image without the .xz
Select a microSD Card
Write
Step 6. Remove the microSD Card
Remove the adapter from the MacBook
Return to previous step and attach heat sinks and insert all of the appropriate connectors, and power on the Raspberry Pi