Install BCM4331 driver for Mac wireless network card on Ubuntu

To automatically install missing drivers, including the wireless network card driver, use the following commands:

sudo apt update
sudo ubuntu-drivers autoinstall

Then, check if the b43 driver is blacklisted by other drivers with the following command, as this can cause the wireless network card driver to not work:

grep b43 /etc/modprobe.d/*

If the output is as follows:

/etc/modprobe.d/blacklist-bcm43.conf:blacklist b43
/etc/modprobe.d/blacklist-bcm43.conf:blacklist b43legacy
/etc/modprobe.d/blacklist.conf:# replaced by b43 and ssb.

Then, you need to execute the following commands to remove the blacklist:

sudo rm /etc/modprobe.d/blacklist-bcm43.conf
sudo modprobe b43

If you have correctly configured the WIFI connection, you can use the ip a command to see three network interfaces:

lo Local loopback interface
enp2s0f0 Ethernet network interface, which is the wired network, similar to eth0, with an assigned IP
wlp3s0 Wireless network interface, identified by the wl prefix indicating wlan, with an assigned IP

Reference#

https://askubuntu.com/a/1380100