How to Install Realtek Rtl8812BU Driver Offline on Debian Bullseye – Step-by-step

Installing Driver

7. 7. Downloading Realtek rtl8812BU Driver

   Download Realtek rtl8812BU Driver in Debian GNU/Linux

   Get Realtek rtl8812BU Driver in Debian

   Realtek Driver Source Code for Debian

   Grab the Zip Archive or clone it with Git.
   
   In this New Post Revision in addition to the default Cilynx Driver choice I’ve added also the Morrownr, RinCat, Aircrack-ng and Gnab eventual Alternatives.
   So in case, then see directly the Developer Github Documentation to Setup it!

8. 8. Extracting Realtek rtl8812BU Driver

   And then Extract Driver Archive into /tmp (Skip in case of Git checkout)
   Possibly Double-Click/Right-Click on Package and Open with Archive Manager:

   
   But if you are in Trouble to Find the Location on Terminal then See: How to Access Downloads Folder from Browser.
   Or from Command Line:

   unzip -d /tmp/ ~/Downloads/rtl88x2bu*.zip

9. 9. Installing Realtek rtl8812BU Driver

   Then to Install Realtek rtl8812BU Wi-fi Driver for Debian
   Access the Target Folder:

   cd /tmp/rtl88x2bu*

   Next to prepare the setup play:

   VER=$(sed -n 's/\PACKAGE_VERSION="\(.*\)"/\1/p' dkms.conf)

   sudo rsync -rvhP ./ /usr/src/rtl88x2bu-${VER}

   Then add it to DKMS:

   sudo dkms add -m rtl88x2bu -v ${VER}

   Again build it with:

   sudo dkms build -m rtl88x2bu -v ${VER}

   Install it into DKMS System:

   sudo dkms install -m rtl88x2bu -v ${VER}

   Long last try to fill it up with:

   sudo modprobe 88x2bu

   Or in case, try Rebooting with:

   sudo reboot

   And you should successfully see your Wifi Adapter magically popping up from nowhere! :)
   Possibly, to load it at Boot time:

   echo 88x2bu | sudo tee -a /etc/modules

   Thanks to Randy C. Will inestimable Work!

Congratulations, your Realtek rtl8812BU Network Device on Debian Bullseye should be now nicely working!