If your Broadcom or Realtek adapter isnt included in the madwifi driver package and you need to manually install it, use the model number to find the linux drivers for your device and substitute for whatever adapter you are using.
Article at https://virtuallyonit.com/2018/09/10/install-a-wireless-adapter-on-kali-linux/ was broken so I found the PDF and here it is.
sudo apt-get install realtek-rtl88xxau-dkms
sudo apt-get update
sudo apt-get upgrade
If the “upgrade” fails, try with the below key:
sudo apt-key adv –keyserver hkp://keys.gnupg.net –recv-keys 7D8D0BF6
Add in USB adapter – In “Virtual Box” this is top menu bar “devices” > “USB” > and
select your adapter