Download http://mirrors.kernel.org/ubuntu/pool/restricted/b/bcmwl/bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu4_amd64.deb Boot into the 4.15 kernel and install
Download http:// mirrors. kernel. org/ubuntu/ pool/restricted /b/bcmwl/ bcmwl-kernel- source_ 6.30.223. 271+bdcom- 0ubuntu4_ amd64.deb
Boot into the 4.15 kernel and install