GNU/Linux openSUSE ALFA Network AWUS1900 Driver Setup Guide
Hi! The linked Tutorial Shows You Step-by-Step How to Install Alfa Network AWUS1900 Wireless AC1900 USB Dongle Driver in GNU/Linux openSUSE Desktops.
And the openSUSE ALFA Network AWUS1900 Setup is based on the Realtek rtl8814AU Chipset Driver Installation.
So the linked guide explain How to Download and Install the rtl8814AU Linux Driver.
In case to check your Adapter Chipset see: How to Check Wireless Device ID on GNU/Linux.

GNU/Linux openSUSE Installing Alfa Network AWUS1900 Wireless Driver