Change the primary domain of a store

Any alias or redirect can become the primary domain. The old primary becomes an alias, so nothing stops working.

1. Add the new domain and point DNS

   If it is not there yet.

2. Make it primary

   Domains & SSL, on the domain choose make primary.

3. Update the store's own URLsMagento: Stores, Configuration, General, Web, Base URLs (or bin/magento setup:store-config:set --base-url). WordPress: Settings, General, WordPress Address and Site Address.
4. Flush caches

   Actions, Flush all caches.

5. Redirect the old domain

   Set the old domain as a redirect so links and rankings follow.