Problem installing Dual Band USB Adapter 2.4/5GHz Wi-Fi on Ubuntu 18.04.4

Solution 1:

First, be certain that the necessary prerequisites are installed:

sudo apt update
sudo apt install --reinstall build-essential dkms git
git clone https://github.com/cilynx/rtl88x2bu.git
cd rtl88x2bu 
VER=$(sed -n 's/\PACKAGE_VERSION="\(.*\)"/\1/p' dkms.conf) 
sudo rsync -rvhP ./ /usr/src/rtl88x2bu-${VER} 
sudo dkms add -m rtl88x2bu -v ${VER} 
sudo dkms build -m rtl88x2bu -v ${VER} 
sudo dkms install -m rtl88x2bu -v ${VER} 
sudo modprobe 88x2bu

Your wireless should now be working.