An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
Hello Grace,
* I am a Microsoft user like you, trying to provide solutions to community members; I am NOT a Microsoft employee.
Please kindly provide more details on the issue you're having. What do you mean you "can't use MS defender"? Is the app not downloading? Not working? Please give a more detailed breakdown about your desired outcome, steps you've taken, you can even provide screenshots if possible.
That will help community members know how best to help you.
- Stephen N.