How do I allow an app not from the app store?

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Tags

1. #tried
2. #privacy
3. #allow
4. #system
5. #anyway
6. #click
7. #operating
8. #preferences
9. #should
10. #noticed
11. #apple
12. #general
13. #under
14. #security
15. #downloaded
16. #setting
17. #button