In this example: my adapter was TP Link Archer T4U
sudo apt-get update
sudo apt-get install dkms
wget https://github.com/abperiasamy/rtl8812AU_8821AU_linux/archive/master.zip
unzip master.zip
cd rtl8812AU_8821AU_linux-master
sudo cp -R . /usr/src/rtl8812AU_8821AU_linux-1.0
sudo dkms add -m rtl8812AU_8821AU_linux -v 1.0
sudo dkms build -m rtl8812AU_8821AU_linux -v 1.0
sudo dkms install -m rtl8812AU_8821AU_linux -v 1.0
Then restart your computer
sudo apt install ubuntu-restricted-extras
Then restart your browser.