1. Apple recently released the macOS Sierra 10.12 system in 2016. After upgrading the system, many users may find that the function used to install the software downloaded from the Internet is missing, that is, the "Any Source" option in the system.

As shown in the figure below, in the "Security and Privacy" setting of the macOS Sierra system, among the applications that are allowed to be downloaded from the following locations, there are only two options: App Store and App Store and approved developers, and only the "Any Source" option Gone.

2. Next, we can open it again through a special system command. To use system commands, first open the Terminal application, which can be found in the "Other" folder of Launchpad, as shown in the figure below：

After opening the Terminal, enter "sudo spctl --master-disable" at the command prompt.

3. And press Enter to execute, as shown below:

Then enter the password of the current Mac user.

4. As shown in the figure below, when the previously entered command is executed and the command prompt is returned successfully, if no error is reported, the execution of the command is successful.

5. Then enter the "Security and Privacy" panel in System Preferences, and find that the "Any Source" option has appeared and is set as the default option. In this way, you can open the application software downloaded from the Internet on your Mac.

6. Then you can install the printer driver.

http://help.beeprt.com/support/solutions/articles/60000561042-install-beeprt-driver-on-mac