An ALIAS record is a virtual record type that we created to provide CNAME-like behavior on apex domains. For example, if your domain is example.com and you want it to point to a host name like myapp.herokuapp.com , then you cannot use a CNAME record, but you can use an ALIAS record.
---- What is an ALIAS record?
 

Some DNS Provider supports ALIAS records. Here is a list in our documents for that. If you had registered an APEX domain --  or root domain/naked domain -- (a domain without www, blog or other prefix) for Shifter, you can also input or select the value of CloudFront Domain  (e.g. def456.cloudfront.net ) which is provided on Shifter's Dashboard.

This article describes two samples for setting up ALIAS records on MuuMuu Domain and Route 53 of AWS.

A CloudFront Domain is provided in the Live > Overview page of your site.
Before accessing your DNS Provider, copy the value of CloudFront Domain ( in this case it is def456.cloudfront.net), and paste into a notepad, evernote, or your favorite stickies.

Please checkout our document: Configuring ALIAS record on MuuMuu Domain

Note: This DNS provider requires using its Custom DNS server. You should use it for your domain. For more details please check its document about it 

Please checkout our document: Configuring ALIAS record on Route 53 of AWS
 

Please ask support desk of your DNS Provider: "do your DNS server supports ALIAS record? If supported, how do I use it?"