How do I redirect to an external domain?

Using Ghost
3

As @Cathy_Sarisky says, please clarify.

If mydomain.com is your old site, and anotherdomain.com is a new Ghost site, you can accomplish redirects using Nginx.

Typically, the old redirects to the new. For example, I have a server block for an old domain that redirects to my Ghost site using rewrite, e.g.,

rewrite ^/(blog/)?$ https://anotherdomain.com/$1 permanent;
rewrite ^/(blog/)?guest-post-submissions https://anotherdomain.com/call-for-guest-bloggers/ permanent;
...