Allow Apps from Anywhere in macOS
Apple made changes to Gatekeeper in macOS to hide the option to install applications from anywhere. By default now, under security settings, you only have the options of App Store and App Store and identified developers. There are three simple ways around this limitation.
Option 1 - Allow Apps from Anywhere to Run
In order to once again have the option to allow apps from anywhere, run a command from the Terminal.
Go back into your security settings and you should see anywhere as an option now. If you would like to return Gatekeeper to its default settings, run the following command.
Option 2 - Allow a Specific Application to Run
To add an exception for a specific app to Gatekeeper, run the following command with the correct path.
Remove an exception for a specific app from Gatekeeper
Option 3 - Right Click Menu
You also have an option to right-click on an app and choose open from the menu.