unzip and extract the deployment package file to the target computer's desktop

Right click the command file and run as admin.  Ignore the warning message.

Additional prompt will appear.
Type "Y" and enter when prompted.
Eventually, it will say of the onboarding is successful.
Press any key to complete the installation.

Please note, it may take as much as 30 minutes for the device to show up in the defender portal.

To test if the onboarding is done successfully, use this command in the command prompt as administrator:
powershell.exe -NoExit -ExecutionPolicy Bypass -WindowStyle Hidden $ErrorActionPreference = 'silentlycontinue';(New-Object System.Net.WebClient).DownloadFile('http://127.0.0.1/1.exe', 'C:\\test-MDATP-test\\invoice.exe');Start-Process 'C:\\test-MDATP-test\\invoice.exe'

The defender portal will prompt a notification within 5-30 minutes.