Devices using the Realtek AC600 & AC1200 chipsets, such as the Edimax EW-7811UTC and Edimax EW-7822UAC, require drivers that have not been merged with the linux kernel and do not come with most linux distros(yet). Follow this guide to install them yourself!
Make sure you have the required build packages
sudo apt-get install linux-headers-generic build-essential git
Download the updated source code
git clone https://github.com/scrivy/rtl8812AU_8821AU_linux.git
Compile the kernel module
sudo make install
sudo modprobe 8812au