I just realised it's not available. How do I manually install it?
websiteforstudents.com
How to Add Microsoft Defender Exclusions on Windows 11 - Website for Students
This post shows students and new users steps to add an exclusion to Microsoft Defender on Windows 11. Microsoft Defender (formally Windows Defender) will scan

My Computer
System One
-
- OS
- Win 11
- Computer type
- PC/Desktop
- CPU
- Ryzen 3600
- Motherboard
- MSI B450 Tomahawk Max
- Memory
- GSkill RipJawz 16Gbx2
- Graphics Card(s)
- GTX960
- Screen Resolution
- 2560x1440
- Hard Drives
- WD750 SSD 1TB
- PSU
- 650w FSP