open Terminal app

Copy and paste and run command sudo mdatp config tamper-protection enforcement-level --value disabled

Input your password.

Copy and paste and run command sudo /Applications/Microsoft\ Defender.app/Contents/Resources/Tools/uninstall/uninstall

You will be prompted to allow terminal to administer your computer. click allow

Defender should now be removed. If you open Kandji self service and navigate to Microsoft Defender under the security section. click the 3 dots next to Open and select reinstall.