Hi,
You can enable /etc/rc.local as follows:
Create a bash file /etc/rc.local with the commands you want to execute at boot time and make it executable. Execute the following command:
sudo /lib/systemd/system-generators/systemd-rc-local-generator
This command will create the rc-local.service files in /lib/systemd/system to execute /etc/rc.local at boot time.
Regards,
GW