To install an application that was downloaded from somewhere other than the AppStore, you need to confirm the installation in the Security & Privacy section. To confirm the installation, do the following:
- After downloading the app, launch it. A warning regarding the presence of malware or the inability to verify the developer will appear on the screen.
- Then open System Preferences and go to Security & Privacy.
- Unlock the interface in the General tab. To do this, click the lock and type in your password. Next, click the Confirm login button.
- In the subsequently opened window click the Open button to start the application installation.