Install If You Want to Use DeX for PC
With the release of Android 10, Samsung’s DeX for PC solution now supports the Galaxy S9 and Galaxy S9+.
Samsung DeX for PC, a feature that rolled out alongside the Galaxy Note 10, allows you to connect your phone to a Windows computer or a Mac and use it in a desktop environment. You only need a USB cable.
Using your device in this manner is perfect for getting work done or playing mobile games with a mouse and keyboard.
You can download DeX for PC for Windows or Mac from Samsung's website.