Install firmware-b43legacy-installer by entering the following commands in the terminal:
sudo apt update sudo apt install firmware-b43legacy-installer
Description:
firmware installer for the b43legacy driver
This package downloads and installs the firmware needed by the b43legacy kernel driver for some Broadcom 43xx wireless network cards. . Supported chipsets: * BCM4301; * BCM4306/2; * BCM4306.
Homepage: http://wireless.kernel.org/en/users/Drivers/b43
Version: 1:019-3
Section: multiverse/kernel