Use wildcard subdomains to redirect visitors from non-existent subdomains to one of your websites, commonly, to your main website. The typical use cases of this feature are:
For example, you do not have the vps-limited-offer subdomain but wish to forward users from limited-vps-offer.example.com to example.com.
It is a widespread mistake to mistype a website name if it has the leading www prefix (for example, typing ww.example.com).
Note: Traffic to existent subdomains will not be affected in any way if you add a wildcard subdomain.
You can add one wildcard subdomain per each of domain names under a subscription. For this, go to Websites & Domains and add a subdomain which name is "*" to one of your domain names. Example: *.example.com. If you wish this subdomain to have a custom set of scripts or website content, specify a custom document root for this subdomain.
Wildcard subdomains act like typical subdomains with the following exceptions: