GNU/Linux Ubuntu 21.04 Installing Broadcom BCM4311/BCM4312/BCM4313 Driver Guide
How to Install Broadcom BCM4311/BCM4312/BCM4313 Wi-fi/Bluetooth Driver for Ubuntu 21.04 Hirsute GNU/Linux – Step by step Tutorial.
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 BCM4311/BCM4312/BCM4313 Driver Installation Guide