GNU/Linux Ubuntu 21.04 Installing Broadcom BCM4331 Driver Guide
Hi! The linked Tutorial shows you Step-by-Step How to Install Broadcom BCM4331 Wi-fi/Bluetooth Driver for Ubuntu 21.04 Hirsute GNU/Linux.
The Package Provides the Source Code for the wl Kernel Modules and makes use of the DKMS Build Utility to Install them for the Running Kernel.
GNU/Linux Ubuntu 21.04 Broadcom BCM4331 Driver Installation Guide