Quick notes for an already well documented method. From a *nix based machine (my iMac while writing this).

ssh-keygen -t rsa -b 4096 -C “me@emailaddress.com”

Choose an id filename – on this instance I set: id_rsademo

ssh-copy-id -i ~/.ssh/id_rsademo me@192.168.0.1

The connection is to the machine on its ip address – this simply has to be able to resolve so it can use DNS

A good write-up is available here: https://www.ssh.com/ssh/copy-id