Addon domain

HI, I made a new addon domain following steps i found online but it doesn't work. I get 2 types of errors when i try to load my website ERR_NAME_NOT_RESOLVED and dns_probe_finished_nxdomain. What could be the problem,should I do something else except to make addon domain what are the correct steps to make addon domain visible on the internet, to make it work. Thanks for answers :)