Photoshop version [Loupedeck]

If the software is install and it detects Photoshop how does the software interface with Photoshop.  For example it could act as a keyboard or a mouse or a pens and interface with Photoshop as a device Photoshop supports.

I did a search and saw a video of  a young woman editing a photo in Photoshop.  She has assigned keys one the device to Photoshop actions bud did not state how the was done of or pressing the key communicated with Photoshop.   It is easy for a program to shove key strokes to an application.   But to play a action with you keyboard you must assign a Fn key to the Action in the action palette.

In the video she use dials to do mouse like things like touch screen touch pads and pens.  It is possible to communicate with  action like a keyboard and mouse and a key could play an action of configured in the action palette.   What I trying to point out something must be added or configure into Photoshop just to play an action.  The action to be played must be in Photoshop how did it get in Photoshop.