This feature will be released in v122 of cPanel & WHM as experimental due to the risky nature of AlLIAS records and that it is still not yet a fully supported record type. Please use at your own risk!

More about the risk:

Alias DNS records are often used to point a domain name to an external service, such as a SaaS provider or front-end load balancer, but this practice is risky for several reasons. These records are not RFC-compliant and their behavior is inconsistent between different implementations, leading to potential compatibility issues and configuration errors. If the external service changes its IP address, your site may become inaccessible due to propagation delays and caching issues. Alias records can introduce additional latency, dependency on external services, and increase the complexity of DNS management. They may also conflict with existing A or AAAA records, cause security issues such as DNS hijacking or spoofing, and break DNSSEC calls. Because they are not standardized, they might lose support without warning, adding to the overall risk.