Hi Tom, I’m so sorry, I always get this backwards. resolv.conf gets overwritten by dhcpcd. To make the changes stick, edit the file /etc/dhcpcd.conf and add the following line to the end of the file:
static domain_name_servers=1.1.1.1 1.0.0.1
Then restart dhcpcd:
sudo service dhcpcd restart
If everything goes well you should end up with two new nameserver lines in resolv.conf, which will stick on reboot.