First, let’s determine why you need the extension for the program Photoshop?
First, using this kind of components, you can extend the basic features of the program, as well as to reduce the time for certain tasks.
For example, installing an extension that allows to split the image in half or more equal parts, you can not spend extra steps during subsequent processing of the material.
So, go to the menu Photoshop – Window – Extensions to look at the available components.
You can click on any of them to see how it works, but we need to establish a new, simply open this application with two clicks of the mouse, or go to a special program called Adobe Extension Manager (usually it is supplied together with the main set Adobe Photoshop).
After this the usual way to install the extension and restart Photoshop before the changes take effect.
Of course, accept the terms of the agreement (if required).