Hi,
This post is just to share with you instructions to install the WiFi USB dongle Dlink DWA-121
The USB WiFi is based on the rtl8188eu and not the RTL8192CU as some websites mention
Write these instructions in the Terminal and the available WiFi network will appear in the network manager
sudo apt-get install git dkms
git clone https://github.com/jeremyb31/rtl8188eu.git
sudo dkms add ./rtl8188eu
sudo dkms install 8188eu/1.0
Enjoy!