When you launch your WordPress site on Shifter, you may notice that some of the URLs within the site have changed. For example, if you migrated your site from example.com, the new URL will appear as abc-123-foo.app.getshifter.io. You can also see this in places within your theme where URLs are displayed, such as in email addresses using the same domain.
About Site URLs in WordPress
The reason for this URL change is that Shifter searches for and replaces the site URL during the deployment process. When Shifter deploys your site, the old URL is replaced with the current container URL.This process ensures that links within the site remain valid even after Shifter changes the site URL.
About Site URLs for Static Sites
When generating a static version of the site, Shifter searches for the container URL and replaces it so that it matches the web address of the static site.If you have already configured a custom domain for your site, that web address will be used. If you have not configured a custom domain, a temporary Shifter URL will be used.