Symptoms
After updating to version 106 of the cPanel software, the "Addon Domains," "Aliases," and "Subdomains" interfaces no longer appear under the "Domains" area of cPanel.
Description
"Addon Domains," "Aliases," and "Subdomains" were deprecated in cPanel version 100 and have been removed in version 106. The functionality of those interfaces has been consolidated to the "Domains" interface.
106 Release Notes: Removed the Addon Domains, Alias Domains and Subdomains features
Workaround
The following articles provide the instructions for creating addon domains, aliases, and subdomains.