URL of site showing IP not Domain
I have a wordpress site, hosted on digital ocean with a domain from 1&1. When I type in the domain it correctly goes to the site, but the URL displays the IP not the domain.
I have tried changing the Site Address (URL) in wordpress settings but this seems to leave me in an endless redirect, where the domain redirects to the IP which redirects to the domain etc.
What do I need to do to get a user to see the domain rather than the URL.