It's the argument to --resolve, not the desired URL. --resolve <[+]host:port:addr[,addr]...> Provide a custom address for a specific host and

It's the argument to --resolve, not the desired URL. --resolve <[+]host:port:addr[,addr]...> Provide a custom address for a specific host and port pair. Using this, you can make the curl requests(s) use a specified address and prevent the otherwise normally resolved address to be used. Consider it a sort of /etc/hosts alternative provided on the command line.