Well, I provided you the link to the instruction on how to enable RPMFusion, here it goes again - RPMFussion, I don’t know what to add more here. After you enable both free and nonfree repositories, you should update your system and reboot before continuing. The command to update (respond ‘yes’ to installation prompts, unless you disagree 
):
sudo dnf update
After the reboot you will have to install both akmod-wl & broadcom-wl with this command:
sudo dnf install akmod-wl broadcom-wl
Reboot, it will take a bit longer that usual as drivers will be built and installed behind the scenes. Wait for login screen to appear, login and check if the option to join WiFi appeared.