At first check the card

inxi -Nn

… if

Device-2: Broadcom BCM4311 802.11a/b/g driver: b43-pci-bridge

…. then

The fix is to re-install firmware-b43-installer.

Try first.

sudo rfkill unblock all
sudo apt update
sudo apt-get --reinstall install firmware-b43-installer
sudo modprobe -r b43
sudo modprobe b43

If you have other net device, you can use the next way.

sudo rfkill unblock all
sudo apt update
sudo apt purge firmware-b43-installer
sudo apt install firmware-b43-installer
sudo modprobe -r b43
sudo modprobe b43