Controling browser using application controller from Unity

I'm developing an interactive kiosk system. The system required 2 interfaces from 2 monitors (web browser + controller from unity). The controller is an application built from Unity consist simple button to control the web browser. The button's function is to navigate the slide movement of the webpage. The figure below shown an example how the system should work.

The problem is, how to interact the web browser from the Unity application? Is there any software to use rather than scripting the HTML (im bad at it)?

I've already used multiplayer api such as Photon and Mirror but it seems both doesnt meet my target. Therefore, is there any options? feel free to leave any idea and im open to any suggestions. Thank you.