You can use the byobu-enable command. See the related man page. To reverse the change, use byobu-disable.

You can use the byobu-enable command. See the related man page. To reverse the change, use byobu-disable.

byobu-enable places a line at the end of ~/.profile. This means it only takes effect for login shells, i.e. via SSH or the VTs. If you're using LXTerminal, it may work if you move that line to ~/.bashrc instead.