Im trying to get a D-link DWA-181 wireless usb device working, but drivers arent recognized in the additional drivers section of Software & updates. The driver is downloaded to the Downloads file. Thank you.
First try to install Realtek firmware.
sudo apt install firmware-realtek
Maybe you don’t need that driver.
Not sure thouhg, but worth a try before messing with other things.
Update:
Now I checked, that Debian 10 firmware-realtek package provides RTL8822BE firmware (rtlwifi/rtl8822befw.bin).
I bet Lubuntu 18.04 provides the same set of drivers, so I start feel confident, installing that package will make your dongle work.
Come back with the result, as always, I may be wrong…